CN1575517A - Integration of ald tantalum nitride and alpha-phase tantalum for copper metallization application - Google Patents

Abstract

The present invention provides a method for forming metal interconnects on a substrate. In one aspect, the method comprises depositing a refractory metal-containing barrier layer having a thickness less than 2 nm such that it exhibits a crystal-like structure and sufficient to inhibit atomic migration over at least a portion of the metal layer; by alternately introducing one or more A pulse of a metal-containing compound and one or more pulses of a nitrogen-containing compound, depositing a seed layer on at least a portion of the barrier layer; and depositing a second metal layer on at least a portion of the seed layer to form an interconnect.

Description

As the ald tantalum nitride on the barrier layer that is used for copper metallization and α tantalum mutually

Technical field

Embodiments of the invention relate to the method that is used to prepare integrated circuit (IC)-components.More specifically, embodiments of the invention relate to and utilize one or more cyclical deposition process to form metal interconnect structure.

Background technology

Because the physical dimension of integrated circuit (IC) device is reduced to inferior 1/4 micron scope in proportion, so resistance and current density have become the factor of being badly in need of consideration and improving.Multilayer interconnect structure provides the conductive path that runs through the IC device, and IC device wherein is formed in the higher structure (feature) of depth-width ratio (aspect ratio), comprises joint, connector, through hole, line (line), lead and other structures.The typical method that go up to form interconnection at substrate (substrate) comprise deposition one or more layers, etching one deck at least wherein forms one or more structures, deposited barrier layer in structure, and deposit one or more layers and fill up structure.Usually, be configured in formation in the dielectric layer that is arranged between lower floor's conductive layer and the upper strata conductive layer.Be interconnected in and form in the structure to connect upper strata conductive layer and lower floor's conductive layer.Form of the generation of these interconnect fabric reliably, and the current densities on single substrate and the matrix (die) and the raising of quality are important to circuit.

Recently, because the resistivity of copper and alloy thereof is less than aluminium, so copper has become the first-selected metal of filling the higher interconnect fabric of sub-micron, depth-width ratio.But copper is easier to be diffused in the material on every side, and can change the electronic device characteristics (for example conductive path between cambium layer) of adjacent layer, thereby has reduced the reliability of entire circuit, and may cause device failure.

Therefore, deposited barrier layer prevents or hinders the diffusion of copper atom before copper metallization.Refractory metal is contained on the barrier layer usually, for example tungsten, titanium, tantalum and nitride thereof, and the resistivity of all these materials is all greater than copper.Be deposited barrier layer in structure, the barrier layer must be deposited on the bottom surface and sidewall thereof of structure.Therefore, the additional amount on the barrier layer on the structure bottom has not only increased the all-in resistance of structure, and becomes the obstacle between the metal interconnected and lower metal interconnection in the upper strata of multilayer interconnect structure.

Therefore, the improving one's methods of formation metal interconnect structure that needs a kind of resistance minimum that make interconnection.

Summary of the invention

The invention provides a kind of metal interconnected method that is used on substrate, forming.On the one hand, this method comprises that deposition contains the barrier layer of refractory metal, and the thickness on described barrier layer presents the crystalloid structure, and is enough to suppress the atomic migration at least a portion metal level.The pulse by alternately introducing one or many containing metal compound and the pulse of one or many nitrogen-containing compound, deposit seed at least a portion barrier layer, and deposition second metal level generates interconnection at least a portion crystal seed layer.

On the other hand, this method is included in and deposits the first metal layer on the substrate surface; By the pulse of alternately introducing the one or many titanium-containing compound, the pulse of one or many silicon-containing compound and the pulse of one or many nitrogen-containing compound, deposit thickness is less than the titanium silicon nitride layer of about 20 dusts at least a portion the first metal layer; Deposition pairing gold crystal seed layer, and at least a portion pairing gold crystal seed layer, deposit second metal level.

On the other hand, this method also is included in deposit thickness at least a portion metal level and stops less than the bilayer of about 20 dusts, deposition pairing gold crystal seed layer, and at least a portion pairing gold crystal seed layer deposition second metal level.Bilayer stops and comprises by alternately introducing first tantalum nitride layer that pulse that one or many contains the pulse of tantalum compound and one or many nitrogen-containing compound deposits and the 2nd α tantalum layer mutually.

On the other hand, this method is included in and deposits the first metal layer on the substrate surface; Contain the pulse of tantalum compound and the pulse of one or many nitrogen-containing compound by alternately introducing one or many, deposit thickness is less than the tantalum nitride barrier layer of about 20 dusts at least a portion the first metal layer; Deposition pairing gold crystal seed layer, the metal that it comprises copper and is selected from aluminium, magnesium, titanium, zirconium, tin and combination thereof; And at least a portion pairing gold crystal seed layer, deposit second metal level.

Description of drawings

For at length learning and understand above-mentioned feature of the present invention, can be with reference to illustrated in the accompanying drawings embodiment, thus the present invention of above brief summary is described more specifically.But, should notice that accompanying drawing has only illustrated exemplary embodiments of the present invention, therefore should not think to limit its scope, because the present invention includes other equivalent embodiment.

Fig. 1 illustrates the treatment process order according to various embodiment as described herein.

Fig. 2 A-2D is the schematic cross-sectional view according to the exemplary wafer of the different phase of the interconnection preparation of embodiment as described herein.

Fig. 3 illustrates the schematic part cross section that is used for forming the exemplary process chamber 200 of thin barrier layer according to the cyclic deposition technique of describing here.

Fig. 4 illustrates the schematic plan view that is suitable for carrying out interconnection preparation as described herein exemplary set beam tool in proper order.

Fig. 5 is transmission electron microscope (TEM) image that wherein has the structure of the titanium nitride barrier layer that deposits according to deposition technique as described herein.

Fig. 6 is the TEM image of the part viewgraph of cross-section of expression multilayer interconnect structure.

Embodiment

The invention provides the technical process sequence that forms one or more interconnection structures.Compare with the interconnection of prior art, the interconnection structure that forms according to embodiment as described herein has lower all-in resistance rate and better electrical property, is particularly useful for making the logical construction of using in memory and the integrated circuit preparation.The formation of described interconnection structure comprises the formation that is deposited on thin barrier layer on bottom (underlying) metal level, is deposited on the crystal seed layer on the described barrier layer and is deposited on the base metal layer on the described crystal seed layer to small part to small part to small part.Terminology used here " interconnection " refers to any conductive path of formation in the integrated circuit.Terminology used here " base metal (bulkmetal) " refers to form other metals that interconnection structure deposits with respect to being used for, and Chen Ji amount of metal is bigger here.

Fig. 1 illustrates the order of technological process according to an embodiment of the invention.At first, for example shown in step 480, thin barrier layer to small part is deposited on the back lining basal surface, for example lower metal interconnection or metal gate.Carry out barrier deposition according to circulation layer deposition technique as described herein,, and allow bottom metal layer to continue growth to pass the barrier layer and enter in the metal level metal interconnected or deposition subsequently of upper strata so that excellent barrier properties is provided.On the one hand, the barrier layer is to contain high melting metal layer, for example tantalum, titanium and tungsten, and can comprise the refractory metal nitride material, for example tantalum nitride (TaN).On the other hand, the barrier layer is TaN and the α thin bilayer of tantalum mutually.On the other hand, the barrier layer can also be the ternary material that is formed by the compound that contains refractory metal, silicon-containing compound and nitrogen-containing compound.The barrier layer also can be used as wetting layer, adhesive layer or the glue-line of follow-up metallization processes.

Here used " thin layer " refers to be deposited on the material layer on the substrate surface, about 20 dusts of thickness or still less, for example about 10 .The electronics of the so thin consequently adjacent metal of the thickness on barrier layer interconnection can tunnelling be crossed the barrier layer.Therefore, the barrier layer is passed through to reduce the all-in resistance rate, thereby provides good device reliability to significantly improve metal interconnected electrical property.

The thin barrier layer that deposits according to cyclic deposition method described here demonstrates epitaxially grown phenomenon.In other words, the barrier layer presents identical with bottom or essentially identical crystallization property.As a result, what grow is monocrystalline substantially, makes that the interface between barrier layer and the bottom does not have the space to form.Equally, the metal level that is deposited on subsequently on the barrier layer presents identical or essentially identical epitaxial growth characteristic, promptly continues to form monocrystalline.Therefore, do not generate the space at the interface at this.The structure of the single crystal-like of gained has been eliminated the formation in space, thereby has significantly increased the reliability of device.Mono-crystalline structures has also reduced the all-in resistance of interconnection when still providing excellent barrier properties.And we believe that the growth of monocrystalline has reduced the susceptibility to electromigration and stress migration owing to similar and uniform crystal orientation on the interconnect material interfaces.

Here used " cyclic deposition " refers to introduce continuously two or more reactive compounds to deposit monolayer material on substrate surface.This two or more reactive compounds are reaction zones of alternately introducing process chamber.Separate various reactive compounds by time delay, so that every kind of compound sticks on the substrate surface also/or reacts on substrate surface.On the one hand, first precursor or compd A carry out very first time delay after being imported in the reaction zone by pulse.Then, second precursor or compd B carry out second time delay after being imported in the reaction zone by pulse.If for example the ternary material of titanium silicon nitride is desired, after then for example the 3rd compound (C) is imported in the reaction zone by quantitative/pulse, carry out the 3rd time delay.During each time delay, for example the inert gas of argon gas is introduced in the process chamber, comes any residual reactive compounds of cleaning reaction district or removal reaction zone.Perhaps, purgative gas flows in whole deposition process serially, and making only has purgative gas to flow during the time delay between the reactive compounds pulse input.Reactive compounds is by alternately pulse input, until form desired film or thicknesses of layers on substrate surface.

Here used " substrate surface " refers to carry out any substrate surface that film is handled thereon.For example, depend on application, substrate surface can comprise any other materials of silicon, Si oxide, doped silicon, germanium, GaAs, glass, sapphire and for example metal, metal nitride, metal alloy and other electric conducting materials.Substrate surface also can comprise for example dielectric material of silicon dioxide and carbon doped silicon oxide.

Here used " pulse input " or " quantitatively input " mean a certain amount of specific compound by off and on or in the reaction zone of discontinuous introducing process chamber.The duration of depending on pulse, the amount of the specific compound in each pulse can change in time.The duration of each pulse is variable, and this depends on many factors, the volatility/reactivity of the volume capacity of for example used process chamber, the vacuum system that is coupled to described process chamber and specific compound itself.

Term " compound " is intended to comprise one or more precursors, oxidant, reducing agent, reactant and catalyst, and combination.Term " compound " also is intended to comprise one group of compound, for example when two or more compounds are introduced into processing unit simultaneously.For example, one group of compound can comprise one or more catalyst, and one or more precursors.Term " compound " for example also is intended to comprise by dissociating or ionization is one or more precursors, oxidant, reducing agent, reactant and the catalyst of activated state or excitation state or its combination.

We believe that physical absorption on substrate surface, absorption, absorption or the used physical attractiveness of chemisorbing monolayer reactant are self-limited types, this is because because substrate surface has limited the available site of reactant, so only have an individual layer to be deposited on the substrate surface at given impulse duration.In case limited site occupied by reactant, then the further deposition of reactant will be obstructed.Can repeat this circulates and reaches the layer of desired thickness.

Still with reference to Fig. 1, shown in step 485, crystal seed layer to small part is deposited on the barrier layer.Can utilize any conventional deposition technique, for example chemical vapor deposition (CVD), physical vapor deposition (PVD), plating or electroless plating come deposit seed.Preferably, crystal seed layer conformally (conformally) is deposited on the bottom barrier layer, and formed thickness is between about 100 -500 .On the one hand, crystal seed layer is traditional copper crystal seed layer.On the other hand, crystal seed layer is a pairing gold crystal seed layer.Exemplary pairing gold crystal seed layer comprises: 1) utilize the unadulterated copper that contains the target material of unadulterated copper and deposit, 2) utilize the copper-aluminium target material of the aluminium contain 2.0 atomic percents of having an appointment and the copper alloy of the aluminium that contains 2.0 atomic percents of having an appointment that deposits, 3) utilize the copper-Xi target material of the tin contain 2.0 atomic percents of having an appointment and the copper alloy of the tin that contains 2.0 atomic percents of having an appointment that deposits, and 4) utilize the copper-zirconium target material of the zirconium that contains 2.0 atomic percents of having an appointment and the copper alloy of the zirconium that contains 2.0 atomic percents of having an appointment that deposits.

Shown in step 487, the base metal layer partly is deposited on the crystal seed layer at least.Also can utilize any conventional deposition technique, for example chemical vapor deposition (CVD), physical vapor deposition (PVD), plating or electroless plating come depositing metal layers.Metal level preferably includes any electric conducting material, for example aluminium, copper, tungsten or its combination.

Fig. 2 A-2D is the schematic diagram in the exemplary interconnect structure of the different phase of preparation.Fig. 2 A shows the bottom metal layer 110 that is formed with dielectric layer 112 on it.Fig. 2 B shows to small part and is deposited on barrier layer 130 on the bottom metal layer 110.Bottom metal layer 110 can contain any conducting metal, for example aluminium, copper, tungsten or its combination, and can form the part of interconnect fabric, and for example connector, through hole, joint, line, lead, but also can be used as the part of metal gate electrode.Fig. 2 C shows to small part and is deposited on crystal seed layer 140 on the barrier layer 130, and Fig. 2 D shows to small part and is deposited on base metal layer 142 on the crystal seed layer 140.

With reference to Fig. 2 A, dielectric layer 112 can be any dielectric material, comprises no matter being known at present or dielectric material (k≤4.0) that will found low-k.For example, dielectric layer 112 can be the oxide of silicon or the Si oxide that carbon mixes.Utilize traditional known technology, the etched structure 114 that forms wherein of dielectric layer 112.Structure 114 can be connector, through hole, joint, line, lead or other interconnection elements arbitrarily.Usually, structure 114 has vertical sidewall 116 and bottom surface 118, about 4: 1 of its depth-width ratio or bigger, for example about 6: 1.Bottom surface 118 exposes at least a portion of lower metal interconnection 110.

With reference to Fig. 2 B, barrier layer 130 conformally is deposited on the bottom surface 118 and sidewall 116 of structure 114.Preferably; reaction zone by being provided with substrate in it provides one or more pulses that contain tantalum compound with the flow velocity of about 100sccm-1000sccm in about 1.0 seconds or shorter period; and in about 1.0 seconds or shorter period, provide the pulse of one or more nitrogen-containing compounds with the flow velocity of about 100sccm-1000sccm; about 20 of deposit thickness or thinner tantalum nitride are contained in the barrier layer, preferred about 10 .The exemplary tantalum compound that contains comprises: t-butyl imino group-three (diethylamino) tantalum (TBTDET); Five (ethylmethylamino) tantalum (PEMAT); Five (dimethylamino) tantalum (PDMAT); Five (diethylamino) tantalum (PDEAT); T-butyl imino group-three (diethylmethyl amino) tantalum (TBTMET); T-butyl imino group-three (dimethylamino) tantalum (TBTDMT); Two (cyclopentadienyl group) tantalumization three hydrogen ((Cp) ₂TaH ₃); Two (methyl cyclopentadienyl) tantalumization three hydrogen ((CpMe) ₂TaH ₃); Its derivative; And combination.Exemplary nitrogen-containing compound comprises: ammonia; Hydrazine; Methyl hydrazine; Dimethylhydrazine; The t-butyl hydrazine; Phenylhydrazine; Azo group iso-butane (azoisobutane); Azido ethane; Its derivative; And combination.

Should be appreciated that, these compounds or arbitrarily other above unlisted compounds at room temperature can be solid, liquid or gas.For example, PDMAT at room temperature is a solid, and TBTDET at room temperature is a liquid.Therefore, before introducing process chamber, non-vapor precursor will be passed through distillation or evaporation step, and this all is well known in the art.As known in the art, for example the carrier gas of argon gas, helium, nitrogen, hydrogen or its mixture also can be used to help handle the compound input indoor.

Carry out each pulse input in order, and the independent non-reactive gas stream of the speed that is accompanied by between about 200sccm-1000sccm.Independent non-reactive gas stream can be imported between the pulse input of each reactive compounds pulsedly, perhaps can introduce independent non-reactive gas stream in whole deposition process continuously.No matter be pulse or continuous, independent non-reactive gas stream plays the effect of any excess reactant of removing reaction zone, thereby prevent that reactive compounds from carrying out unwanted gas-phase reaction, and also play the effect of any byproduct of reaction of removing process chamber, be similar to purgative gas.Except these effects, flowing separately of continuous non-reactive gas helps reactive compounds is transferred to substrate surface pulsedly, is similar to carrier gas.Terminology used here " non-reactive gas " refers to can not participate in a kind of gas or the admixture of gas that metal level forms.Exemplary non-reactive gas comprises argon gas, helium, nitrogen, hydrogen or its combination.

" reaction zone " be intended to comprise with just in any space that processed substrate surface fluid is connected.Reaction zone can be included in the interior any space of process chamber between source of the gas and the substrate surface.For example, reaction zone comprises that substrate is arranged on any space in proportional valve downstream wherein.

The duration of each pulse input/quantitatively input is variable, and can be conditioned, for example can adapt to whereby process chamber volume capacity and with the capacity of the vacuum system of its coupling.In addition, the quantitative input time of compound can according to the type of the flow velocity of compound, the pressure of compound, the temperature of compound, the type of proportional valve, used control device, and the adsorption capacity of compound on substrate surface change.Quantitatively also can change input time based on the geometry of the type of the layer that just is being formed and the device that just is being formed.

Usually, were generally 1.0 seconds the duration of each pulse input or " quantitatively input time " or still less.But, quantitatively can arrive several seconds in several microseconds to several milliseconds input time, even in the scope of a few minutes.Generally, quantitatively answer long enough input time, thereby for the compound of certain volume provides sufficient time absorption/chemisorbed to the whole surface of substrate, and form compound layer thereon.

Fig. 3 illustrates the schematic part cross section of exemplary process chamber 200, and this process chamber can utilize circulation layer deposition, ald, digital chemical vapour deposition (CVD) and rapid chemical gas phase deposition technology to form the barrier layer.Term " circulation layer deposition ", " ald ", " digital chemical vapour deposition (CVD) " and " rapid chemical vapour deposition " can be used here with intercoursing, refer to gas phase deposition technology, introduced in order by two or more compounds of this technology in the reaction zone of process chamber, and on substrate surface, deposited layer material.This process chamber 200 can obtain from the Applied Materials of the Santa Clara that is positioned at California, and its cutline is as follows.The commonly assigned U.S. Patent application No.10/032 that is entitled as " Gas Delivery Apparatus and Method For AtomicLayer Deposition " that more detailed description can be submitted in December 21 calendar year 2001, find in 284, quoted its content here as the reference data.

Process chamber 200 can be integrated in the integrated processing platform, for example also can be from the Endura of Applied Materials's acquisition ^TMPlatform.Endura ^TMThe commonly assigned U.S. Patent application No.09/451 that is entitled as " Integrated Modular Processing Platform " that the details of platform was submitted on November 30th, 1999 has description in 628, has quoted its content here as the reference data.

With reference to Fig. 3, chamber 200 comprises chamber body 202 and the substrate support 212 that sets within it, and chamber body 202 has the bar valve 208 that forms in its sidewall 204.Substrate support 212 is installed in and promotes on the motor 214, raises and reduces substrate support 212 and substrate 210 disposed thereon.Substrate support 212 also can be included in and be used in the processing procedure substrate 210 is fixed on vacuum cup, electrostatic chuck or holding ring on the substrate support 212.And, can utilize the heating element of embedding, for example resistance heater comes heated substrate support 212, maybe can utilize the radiant heat that for example is arranged on the heating lamp on the substrate support 212 to come heated substrate support 212.Clean ring 222 and can be arranged on the substrate support 212, thereby limit flushing channel 224, it provides purgative gas to prevent the deposition on the peripheral part of substrate 210.

Air delivery device 230 is arranged on the top of chamber body 202, and being used for provides gas to chamber 200, for example handles gas and/or purgative gas.Vacuum plant 278 links to each other with suction channel 279, is used for gas in the evacuated chamber 200, and helps to keep pressure desired in the suction district 266 of chamber 200 or desired pressure limit.

Air delivery device 230 comprises chamber cap 232, and it has the interior inflation channel 234 that forms of part therebetween.Chamber cap 232 also comprises the bottom surface 260 that extends to the peripheral part of chamber cap 232 from inflation channel 234.The size of bottom surface 260 and shape can cover the substrate 210 that is arranged on the substrate support 212 fully.The internal diameter of inflation channel 234 237 increases to the bottom 235 of the bottom surface 260 of adjacent chamber lid 232 gradually from top.Along with gas stream overexpansion passage 234, because the expansion of gas, the gas velocity that flows by it can reduce.The gas prompt drop that reduces is low blows away the possibility of the lip-deep reactant that is adsorbed on substrate 210.

Air delivery device 230 also comprises at least two high-speed trigger valve 242 with one or more ports.At least one valve 242 is every kind of reactive compounds special uses.For example, first valve is the compound special use that contains refractory metal, for example tantalum and titanium, and second valve is the nitrogen-containing compound special use.If wish ternary material, then the 3rd valve is another kind of compound special use.For example, if silicide is desired, then another kind of compound can be siliceous compound.

Valve 242 can be arbitrarily can be accurately and repeatedly with the valve in the compound input chamber body 202 of short pulse.In some cases, the ON/OFF cycle period of valve 242 or pulse are about 100 milliseconds or shorter.Valve 242 can directly be controlled by component computer, large-scale computer for example, or by controlling towards the nonshared control unit of specific chamber/application, the U.S. Patent application No.09/800 of the common pending trial of submitting in March 7 calendar year 2001 that is entitled as " ValveControl System For ALD Chamber " for example, the programmable of describing in detail in 881 (PLC) has been quoted its content here as the reference data.For example, valve 242 can be automatically controlled (EC) valve, is the valve of FR-21-6.35 UGF-APD as the commercially available part number of Japanese Fujikin company.

Be convenient control and the whole device of automatic operation, integrated treating device can comprise the controller 140 that contains CPU (CPU) 142, memory 144 and support circuit 146.CPU 142 can be a kind of computer processor of arbitrary form, and it is used in and controls various transmissions and pressure in the industrial environment.Memory 144 is connected with CPU 142, can be one or more memory that obtains easily, for example random access storage device (RAM), read-only memory (ROM), floppy disk, hard disk or any other forms of digital storage, Local or Remote memories.Software instruction and data can be encoded, and are stored in the memory 144, are used to refer to CPU 142.Support that circuit 146 also is connected with CPU 142, be used for supporting in a conventional manner processor 142.Support that circuit 146 can comprise buffer memory, power supply, clock circuit, input/output circuitry, subsystem etc.

In specific embodiment, by introducing PDMAT circularly to substrate surface and ammonia forms the TaN barrier layer.Be the cyclic deposition of beginning TaN layer, for example the carrier/inert gas of argon gas is introduced in the process chamber 200 to stablize its pressure and temperature.Allow carrier gas to flow continuously in deposition process, making only has argon gas to flow between the pulse input of every kind of compound.After indoor temperature and pressure were stabilized in about 200 ℃-300 ℃ and about 1Torr-5Torr respectively, by the flow velocity of source of the gas 238 with about 100sccm-400sccm, the burst length was about 0.6 second or first pulse of the shorter PDMAT of providing is imported.By the flow velocity of source of the gas 239 with about 200sccm-600sccm, the burst length was about 0.6 second or the shorter pulse input that ammonia is provided then.

Can suspend about 1.0 seconds or shorter between the pulse input of PDMAT and ammonia, preferably suspend about 0.5 second or shorter, more preferably suspend about 0.1 second or shorter.In all fields, the time decreased between the pulse input provides higher treating capacity at least.As a result, also suspend about 1.0 seconds or shorter after the pulse input ammonia, about 0.5 second or shorter, perhaps about 0.1 second or shorter.Source of the gas 240 is provided at the argon gas that flows between about 100sccm-1000sccm, for example about 100sccm-400sccm continuously by each valve 242.On the one hand, when the pulse of ammonia entered, the pulse of PDMAT may be still indoor.Generally, the duration of carrier gas and/or suction evacuation answers long enough to prevent that the pulse of PDMAT and ammonia mixes in reaction zone.

During the about 1.0-5.0Torr of constant pressure, the temperature maintenance of heater is at about 100 ℃-300 ℃.Preferably, depositing temperature is between about 200 ℃-250 ℃.Pulse input, time-out, the pulse input of ammonia and each cycle period that time-out is formed by PDMAT provide the tantalum nitride layer of every circulation thickness between about 0.3 -1.0 .Can repeat the order that this replaces, until reaching desirable thickness, promptly be less than about 20 , for example about 10 .Therefore, this deposition process needs 10-70 cycle period, more specifically 20-30 cycle period.

On the other hand, by one or more contain the pulse input of the pulse input of the compound of refractory metal, one or more nitrogen-containing compounds and the pulse inputs of one or more silicon-containing compounds are provided, deposit the ternary barrier layer of thickness less than about 20 (for example 10 ).Regulate each pulse and cover (step coverage) with the ladder of nitride layer that desired composition, silicon content, thickness, density and refractory metal-silicon is provided.Here used " ternary barrier layer " refers to comprise the material of the composition of three kinds of essential elements, for example titanium, nitrogen and silicon.Exemplary " ternary barrier layer " also can comprise tantalum, nitrogen and silicon.

Under above-mentioned identical process conditions, carry out each pulse input in order, and be attended by independent carrier/inert gas stream.Independent carrier/inert gas stream can be introduced between the pulse input of each reactive compounds pulsedly, perhaps can introduce continuously in whole deposition process.

Preferably, titanium silicon nitride is contained on the ternary barrier layer.In this embodiment, each cycle period comprise pulse input, time-out, the silicon-containing compound of titanium-containing compound pulse input, time-out, nitrogen-containing compound the pulse input and suspend.Exemplary titanium-containing compound comprises four (dimethylamino) titanium (TDMAT), four (ethylmethylamino) titanium (TEMAT), four (diethylamino) titanium (TDEAT), titanium tetrachloride (TiCl ₄), titanium tetra iodide (TiI ₄), titanium tetrabromide (TiBr ₄) and the halide of other titaniums.Exemplary silicon-containing compound comprise silane, disilane, methyl-monosilane, dimethylsilane, chlorosilane (SiH ₃Cl), dichloro-silane (SiH ₂Cl ₂) and three chloro silane (SiHCl ₃).Exemplary nitrogen-containing compound comprises: ammonia, hydrazine; Methyl hydrazine; Dimethylhydrazine; The t-butyl hydrazine; Phenylhydrazine; The azo group iso-butane; Azido ethane; Its derivative; And combination.

Be beginning Ti _xSi _yThe cyclic deposition of N layer is introduced process chamber 200 stable pressure and temperatures wherein with argon gas.This independent argon gas stream flows in whole deposition process continuously, and making only has argon gas to flow between the pulse input of every kind of compound.Independent argon gas stream flows with about 100sccm-1000sccm, for example between about 100sccm-400sccm.On the one hand, after indoor temperature and pressure were stabilized in about 250 ℃ and about 2Torr respectively, with the flow velocity of about 10sccm-1000sccm, the burst length was about 0.6 second or the pulse of the shorter TDMAT of providing is imported.With the flow velocity of about 5sccm-500sccm, the burst length was about 1 second or the shorter pulse input that silane is provided then.With the flow velocity of about 100sccm-5000sccm, the burst length was about 0.6 second or the shorter pulse input that ammonia is provided then.

Can suspend about 1.0 seconds or shorter between the pulse input of TDMAT and silane, preferably suspend about 0.5 second or shorter, more preferably suspend about 0.1 second or shorter.Can suspend about 1.0 seconds or shorter between the pulse input of silane and ammonia, preferably suspend about 0.5 second or shorter, more preferably suspend about 0.1 second or shorter.Also suspend about 1.0 seconds or shorter after the pulse input ammonia, about 0.5 second or shorter, perhaps about 0.1 second or shorter.On the one hand, when the pulse of silane entered, the pulse of TDMAT may be still indoor, and when the pulse of ammonia entered, the pulse of silane may be still indoor.

Under the about 1.0-5.0Torr of constant pressure, the temperature maintenance of heater is at about 100 ℃-300 ℃.By the pulse input of the pulse input of the pulse input of TDMAT, time-out, silane, time-out, ammonia with suspend each cycle period of forming the titanium silicon nitride layer of every circulation thickness between about 0.3 -1.0 is provided.Can repeat the process sequence that this replaces, until reaching desirable thickness, promptly be less than about 20 , for example about 10 .Therefore, this deposition process needs 10-70 cycle period.

On the other hand, thickness is about 20 or still less, and (layer of α-Ta) can be deposited on the binary layer (TaN) or ternary layers (TiSiN) that at least a portion deposits earlier the α phase tantalum of for example about 10 .Can utilize conventional art, for example PVD and CVD deposit α-Ta layer, to form double-deck lamination.For example, double-deck lamination can comprise TaN part that deposits by above-mentioned circulation layer and the α-Ta part that deposits by highly dense plasma physics vapour deposition (HDP-PVD).With respect to β phase tantalum, because the resistance of α phase tantalum is lower, so α is preferred mutually.

Further specify, the α of lamination-Ta part can be utilized ionized metal plasma (IMP) chamber deposition, for example the Vectra that can obtain from the Applied Materials of the Santa Clara in California ^TMThe chamber.The IMP chamber comprises target material, coil and bias substrate bracket component, and also can be integrated into also the Endura that can obtain from Applied Materials ^TMIn the platform.The power application of about 0.5kW-5kW is on target material, and the power application of about 0.5kW-3kW is on coil.The about 13.56MHz of frequency, the power of about 200W-500W also are applied in the substrate support parts so that the substrate biasing.Argon gas flows to indoor with the speed of about 35sccm-85sccm, and with the speed of about 5sccm-100sccm to indoor adding nitrogen.Constant pressure is usually between about 5mTorr-100mTorr, and room temperature is between about 20 ℃-300 ℃.

Above-mentioned barrier film can be benefited from the deposition processes technology of back, for example plasma treatment process or chemical treatment technology.Plasma treatment process can reduce resistance, improves productive rate.Typical plasma treatment can comprise argon plasma, nitrogen plasma or nitrogen and hydrogen plasma.Plasma treatment can be carried out in the same settling chamber that barrier deposition takes place or in the different chambers.If plasma treatment takes place in same chamber, then plasma can be in-situ plasma or the plasma that sent by remote plasma source, for example long-range induction coupled source or microwave source.

Though do not wish to be limit by theory, we believe that for example the plasma treatment of nitrogenize tantalum film goes out the nitrogen content that nitrogen has reduced one or more subgrades by splash, thereby have reduced resistivity.For example, we think that the tantalum nitride layer of crossing with respect to non-plasma treatment, plasma treatment make tantalum nitride layer contain more tantalum.In other words, utilize plasma treatment process, 1: 1 Ta: the N film can change 2: 1 Ta into: the N film.Can obtain for 0.004 micron (40 dust) thick film, its layer resistance approximates 1200 micro-ohm cm or lower nitrogenize tantalum film.

Therefore, other non-chemically reactant gas can be used to physically replace nitrogen, for example neon (Ne), xenon (Xe), helium (He) and hydrogen (H from the barrier layer ₂).Usually,, more wish the atomic mass of the atomic mass of plasma gas atom or molecule near N in order preferentially to eject N, rather than near Ta.But, remove N if specific gas preferentially reacts, and when staying Ta, then can utilize the chemical reaction process process.

The chemical treatment technology process also can reduce resistance, improves productive rate.Typical chemical treatment can comprise and is exposed to aluminium compound or silicon compound.These compounds can include but not limited to DMAH, TMA, silane, dimethylsilane, trimethyl silane and other organic silane compounds.Chemical treatment is usually under the pressure of about 1Torr-10Torr, carry out under about 200 ℃-400 ℃ temperature.After the chemical treatment, observed nitrogenize tantalum film according to said method deposition with respect to not carrying out chemically treated film, its dehumidification ability is improved.

Subsequent deposition treatment process process can be carried out after forming the barrier layer.Perhaps, this processing can be carried out between the deposition of each individual layer, or carries out between the deposition of each cycle period.For example, the treatment process process can be carried out after the layer of the about 0.003-0.005 micron of every formation (30-50 dust), or carries out behind every approximately 7-10 cycle period.

And before deposited barrier layer 130, substrate dielectric layer 112 patterning capable of washing or etching removes natural oxide or other pollutants on surface.For example, at remote plasma source (for example reaction pre-cleaning chamber that can obtain from the Applied Materials of the Santa Clara that is positioned at California), reactant gas is provoked into plasma.By remote plasma source being connected to metal CVD or PVD chamber, also can indoorly finish prerinse at these.Perhaps, the metal deposition chamber with air delivery device can change into by existing gas access (for example being positioned at the gas distribution showerhead of substrate top) and transmit the prerinse gaseous plasma.

On the one hand, reaction prerinse technical process forms the free radical from the plasma of one or more reactant gases, for example argon gas, helium, hydrogen, nitrogen, fluorochemical and combination thereof.For example, reactant gas can comprise carbon tetrafluoride (CF ₄) and oxygen (O ₂) mixture, or helium (He) and Nitrogen trifluoride (NF ₃) mixture.More preferably, reactant gas is the mixture of helium and Nitrogen trifluoride.

After argon plasma was handled, constant pressure was increased to about 140mTorr, and the processing gas of being made up of hydrogen and helium is introduced into treatment region substantially.Preferably, this processing gas comprises about 5% hydrogen and about 95% helium.Produce hydrogen plasma by using about 50 watts-500 watts power.Hydrogen plasma was kept about 10 seconds-300 seconds.

Refer again to Fig. 2 C, can utilize highly dense plasma physics vapour deposition (HDP-PVD) to come deposit seed 140, cover can realize conformal preferably.An example of HDP-PVD chamber is the self-ionized plasma SIP that can obtain from the Applied Materials of the Santa Clara in California ^TMThe Endura that obtains from Applied Materials can integratedly be advanced with it in the chamber ^TMPlatform.Certainly, also can utilize other technologies, for example physical vapour deposition (PVD), chemical vapour deposition (CVD), electroless plating and plating.

Typical SIP ^TMThe chamber comprises target material, coil and bias substrate bracket component.For forming the copper crystal seed layer, the power application of about 0.5kW-5kW is on target material, and the power application of about 0.5kW-3kW is on coil.And the power of about 200W-500W comes bias substrate under the about 13.56MHz of applying frequency.Argon gas flows to indoor with the speed of about 35sccm-85sccm, and with the speed of about 5sccm-100sccm to indoor adding nitrogen.Constant pressure is usually between about 5mTorr-100mTorr.

Perhaps, can pass through any suitable technique, for example physical vapour deposition (PVD), chemical vapour deposition (CVD), electroless deposition or its combination technique deposit the crystal seed layer 140 that contains copper alloy.Preferably, copper-alloy seed layer 140 contains aluminium, and utilizes above-mentioned PVD deposition techniques.In deposition process, the pressure of process chamber maintains between about 0.1mtorr-10mtorr.Target material comprises copper and the aluminium of atomic wts percentage between about 2-10.Target material can be a direct current biasing under the power of about 5kW-100kW.Support can be a rf bias under the power of about 10W-1000W.The deposit thickness of copper-alloy seed layer 140 is at least about 5 , and between about 5 -500 .

With reference to Fig. 2 D, can utilize chemical vapor deposition (CVD), physical vapor deposition (PVD), plating or its to make up and form metal level 142.For example, by containing dimethyl hydrogenation aluminium (DMAH) and hydrogen (H ₂) or argon gas (Ar) but admixture of gas or the reaction deposition of aluminum (Al) of other mixtures that contain DMAH layer, by containing Cu ^{+ 2}(hfac) ₂(hexafluoroacetylacetone copper), Cu ^{+ 2}(fod) ₂(seven fluorine dimethyl octadiene hydrocarbon copper), Cu ^{+ 1}The hfac TMVS (hexafluoroacetylacetone copper trimethyl-ethylene base silane) or the admixture of gas of its combination can deposit CVD copper layer, and by containing tungsten hexafluoride (WF ₆) and the admixture of gas of reducing gas can deposit the CVD tungsten layer.Can deposit the PVD layer by copper target material, aluminium target material or tungsten target material.

And metal level 142 can be the refractory metal compound, includes but not limited to titanium (Ti), tungsten (W), tantalum (Ta), zirconium (Zr), hafnium (Hf), molybdenum (Mo), niobium (Nb), vanadium (V) and chromium (Cr) etc.Usually, refractory metal combines with reactive component, for example chlorine (Cl) or fluorine (F), and provide to form the refractory metal compound with another kind of gas.For example, titanium tetrachloride (TiCl ₄), tungsten hexafluoride (WF ₆), tantalic chloride (TaCl ₅), zirconium chloride (ZrCl ₄), hafnium tetrachloride (HfCl ₄), molybdenum pentachloride (MoCl ₅), columbium pentachloride (NbCl ₅), five vanadium chloride (VCl ₅) or four chromium chloride (CrCl ₄) can be used as the chemical compound gas that contains refractory metal.

Preferably, metal level 142 is a copper, forms in electroplating unit, for example the Electra that can obtain from the Applied Materials of the Santa Clara in California ^TMCu ECP device.Electra ^TMThe CuECP device also can be integrated advances also the Endura that can obtain from Applied Materials ^TMPlatform.

In the commonly assigned U.S. Patent No. 6,113,771 that is entitled as " Electro-deposition Chemistry ", describe copper electrolytes solution and copper electroplating technology, quoted its content as a reference here.Usually, the copper concentration of electroplating bath is greater than about 0.7M, and concentration of copper sulfate is about 0.85, and the pH value is about 1.75.Electroplating bath also can comprise various additives well known in the art.Between 15 ℃-25 ℃ of the bath Wen Zaiyue.Be biased in approximately between-15 volts to 15 volts.On the one hand, positive bias is between about 0.1 volt to 10 volts, and back bias voltage is approximately between-0.1 to-10 volts.

Alternatively, after metal level 142 deposition, can carry out the thermal anneal process process, make wafer be under about 100 ℃ of-400 ℃ of temperature about 10 minutes to 1 hour, preferred about 30 minutes.Introduce for example carrier gas/purgative gas of helium, hydrogen, nitrogen or its mixture with the speed of about 100sccm-10000sccm.Constant pressure maintains between about 2Torr-10Torr.Radio-frequency power is about 200W-1000W under the frequency of about 13.56MHz, and the substrate spacing is preferably between Mill, about 300 Mills-800.

After the deposition, can carry out planarization to the top of resulting structures.Available chemico-mechanical polishing (CMP) device, for example Mirra that can obtain from the Applied Materials of the Santa Clara in California ^TMDevice.Alternatively, between the deposition of above-mentioned succeeding layer, can carry out planarization to the intermediate surface of structure.

Fig. 4 is the schematic plan of exemplary multicell processing unit 600, and it is suitable for being used for carrying out above disclosed sedimentary sequence.The commercially available Endura of Applied Materials of the Santa Clara that this processing unit 600 can be California ^TMDevice.In the U.S. Patent No. 5,186,718 that is entitled as " StageVacuum Wafer Processing System and Method " of authorizing on February 16th, 1993, disclose similar multicell processing unit, quoted its content as a reference here.

Device 600 generally comprises and is used for substrate feeder 600 with from installing the load fixed chamber 602,604 that takes out substrate 600.Usually, be under the vacuum condition, so load fixed chamber 602,604 can be with the substrate " sucking-off " (pump down) in the introducing device 600 owing to install 600.First manipulator 610 can overlap between one or more substrate processing chambers 612,614,616,618 (illustrated have four) at load fixed chamber 602,604 and first and transmit substrate.Each process chamber 612,614,616,618 can be equipped to and can carry out many substrate process operations, for example circulation layer deposition, chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, prerinse, the degassing, location and other substrate processing processes.First manipulator 610 can also arrive one or more transfer chambers 622,624 with substrate transfer, and takes out substrate from transfer chamber.

Transfer chamber 622,624 is allowing substrate in device 600 in the transmission, and is used to keep ultra-high vacuum state.Second manipulator 630 can transmit substrate between transfer chamber 622,624 and the one or more substrate processing chambers 632,634,636,638 of second cover.Be similar to process chamber 612,614,616,618, process chamber 632,634,636,638 can be equipped to and can carry out multiple different substrate process operations, for example circulation layer deposition, chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, prerinse, the degassing, location.If any in the substrate processing chambers 612,614,616,618,632,634,636,638 is unwanted for device 600 specific embodiments of carrying out, all can remove from installing 600.

In a kind of organization plan, each process chamber 632 and 638 can be physical vapor deposition chamber, CVD (Chemical Vapor Deposition) chamber or the cyclic deposition chamber that is suitable for deposit seed; Each process chamber 634 and 636 can be cyclic deposition chamber, CVD (Chemical Vapor Deposition) chamber or the physical vapor deposition chamber that is suitable for deposited barrier layer; Each process chamber 612 and 614 can be physical vapor deposition chamber, CVD (Chemical Vapor Deposition) chamber or the cyclic deposition chamber that is suitable for dielectric layer; And each process chamber 616 and 618 can be to be equipped to be the etching chamber of interconnect fabric etch-hole or opening.This concrete structure scheme of device 600 is to be used for illustrating the present invention, is not to be used for limiting the scope of the invention.

We believe that thickness will stop the growth pattern of lower metal interconnection greater than the refractory metal nitride layer of about 20 dusts.Thickness will be set up the growth pattern of himself uniqueness more than or equal to the refractory metal nitride layer of about 20 dusts, this pattern will at first be adopted by more high-rise interconnection, reach specific thicknesses and set up the pattern of himself until more high-rise interconnection, thereby form different crystal structures.This phenomenon be because: in initial deposition phase, the growth pattern of the layer of subsequent deposition is similar to the growth pattern of its bottom usually, in case but succeeding layer reaches specific thicknesses, then described succeeding layer will present the inherent pattern of himself.

For example tantalum nitride trends towards forming the impalpable structure that thickness is not less than 20 dusts naturally.At thickness during less than about 20 dusts, the growth pattern of similar its bottom of TaN.Therefore, the subsequent copper interconnection layer passes the barrier layer surprisingly and grows, and described barrier layer is the method according to this invention deposition, presents the growth pattern that is similar to the bottom copper-connection.In other words, the TaN barrier layer that thickness is less than or equal to about 20 dusts makes shot copper to grow preferably, makes shot copper can pass TaN barrier layer elongation growth, or briefly, is exactly that copper presents epitaxial growth on tantalum nitride barrier layer.

Fig. 5 is structure 300 transmission electron microscope (TEM) image, and structure 300 has according to above-mentioned deposition technique and the tantalum nitride barrier layer 310 of deposition within it.The depth-width ratio of structure 300 is 5: 1, and forms on the wafer of 200mm.Barrier layer 310 is made up of tantalum nitride, and goes out at 250 ℃, 2Torr deposit.Each cycle period continues about 2 seconds, and has carried out 30 cycle periods.The thickness of tantalum nitride barrier layer 310 is about 15 dusts.As directed, barrier layer 310 is conformal (conformal), shows that ladder covers better in whole structure 300.

Fig. 6 is the TEM image of the part cross section of expression multilayer interconnect structure 400.Multilayer interconnect structure 400 comprises lower floor's copper-connection 405, tantalum nitride barrier layer 410 and upper copper interconnection 420.Barrier layer 410 is passed in the growth of the shot copper of lower floor's copper-connection 405, extends in the upper copper interconnection 420, thereby shows the epitaxial growth of tantalum nitride barrier layer 410.Barrier layer 410 is made up of tantalum nitride, and goes out at 250 ℃, 2Torr deposit.Each cycle period continues about 2 seconds, and has carried out 30 cycle periods.The thickness on barrier layer 410 is about 10 dusts, and this thickness is enough to suppressed copper migration and advances in the dielectric layer.

Utilize the TEM apparatus measures with reference to shown in Fig. 3 and the 4 and barrier layer of describing 310 and 410.Should be appreciated that, this measuring technique and arbitrarily other technology that are used for measuring deposit thickness all have marginal error.Therefore, thickness provided here is similar to, and is to quantize according to present known best technique, but is not intended to limit scope of the present invention.

Following example is intended to provide the non-limitative illustration of one embodiment of the present of invention.

Example:

Utilize cyclic deposition on lower floor's copper layer, to deposit the thick TaN layer that is about 20 .On the TaN layer, deposit the thick copper-alloy seed layer that is about 100 by physical vapour deposition (PVD).Copper-alloy seed layer contains the aluminium that concentration is about 2.0 atomic percents, and is by PVD, utilizes to be about copper-aluminium target material that the aluminium of 2.0 atomic percents forms by concentration and to deposit.Utilize ECP deposition bulk copper layer to fill up structure then.Then at nitrogen (N ₂) and hydrogen (H ₂) environment in, under about 380 ℃ temperature with about 15 minutes of substrate thermal annealing.

The structure all-in resistance significantly reduces, and upper copper layer presents the grain growth that is similar to lower floor's copper layer surprisingly.Compare with the PVD Ta of 50 , the barrier properties of TaN layer presents longer time between failures (TTF).In addition, the TaN layer shows lower contact resistance and diffusion profile closely.The TaN layer also presents excellent morphological characteristic, comprises smooth configuration of surface and pin hole Free Surface.

In addition, the TaN film according to PDMAT as described herein and ammonia process process deposition shows unusual film uniformity.The linear ratio of film thickness and number of deposition cycles, thus accurate THICKNESS CONTROL guaranteed.On the substrate of concurrent present 200mm, for 10 dusts, thickness evenness is 1.8%; For 100 dusts, thickness evenness is 2.1%.Deposited film presents unusual conformal and covers, at least in some result near 100%.

At last, copper-alloy seed layer shows the bonding/wettability to TaN layer excellence.

(PVD) the copper crystal seed layer presents preferred { 111} orientation on the barrier layer of deposition.{ the 111} crystal orientation is preferred, and this is because this orientation provides bigger crystallite dimension, thereby and because bigger crystallite dimension presents electro migration resistance preferably.

Though aforementioned part relates to embodiments of the invention, do not departing under base region of the present invention and the situation by the appended determined scope of claim, can design that of the present invention other are further

Embodiment.

Claims (19)

1. A method of forming a metal interconnect on a substrate, comprising: By alternately introducing one or more pulses of a metal-containing compound and one or more pulses of a nitrogen-containing compound, a barrier layer comprising a refractory metal is deposited to a thickness that exhibits a crystal-like structure and is sufficient to inhibit at least a portion of the metal Atomic migration on layers; depositing a seed layer on at least a portion of the barrier layer; and A second metal layer is deposited on at least a portion of the seed layer. 2. The method of claim 1, wherein the refractory metal-containing barrier comprises tantalum nitride. 3. The method of claim 1, wherein the grain growth of the metal layer extends through the barrier layer into the second metal layer. 4. The method of claim 1, wherein each pulse input is repeated until the refractory metal-containing barrier layer has a thickness of less than about 20 Angstroms. 6. The method of claim 1, wherein the refractory metal-containing barrier layer has a thickness of about 10 Angstroms. 7. The method of claim 1, wherein the alternating pulse input is repeated 10-70 times to form the refractory metal nitride layer. 8. The method of claim 1, further comprising continuously flowing a purge gas during each pulse of the metal-containing compound and each pulse of the nitrogen-containing compound. 9. The method of claim 8, wherein the purge gas comprises argon, nitrogen, helium, or combinations thereof. 10. The method of claim 1, wherein each pulsed input of the metal-containing compound and the pulsed input of the nitrogen-containing compound are separated by a time delay. 11. The method of claim 10, wherein each time delay is long enough for an amount of a metal-containing compound or an amount of a nitrogen-containing compound to adsorb on the substrate surface. 12. The method of claim 11, wherein the time delay is long enough to remove unadsorbed molecules on the substrate surface. 13. The method of claim 1, wherein the nitrogen-containing compound is selected from the group consisting of ammonia; hydrazine; methylhydrazine; dimethylhydrazine; t-butylhydrazine; phenylhydrazine; ethyl ethane; derivatives thereof; and combinations thereof. 14. The method of claim 1, wherein the metal-containing compound is selected from the group consisting of tetrakis(dimethylamino)titanium (TDMAT); tetrakis(ethylmethylamino)titanium (TEMAT); tetrakis(diethylamino)titanium ) titanium (TDEAT); titanium tetrachloride (TiCl ₄ ); titanium tetraiodide (TiI ₄ ); titanium tetrabromide (TiBr ₄ ); t-butylimino-tris(diethylamino)tantalum (TBTDET ); penta(ethylmethylamino)tantalum (PEMAT); penta(dimethylamino)tantalum (PDMAT); penta(diethylamino)tantalum (PDEAT); t-butylimino-tris(dimethylamino)tantalum (TBTDMT); bis(cyclopentadienyl)tantalum trihydrogen ((Cp) ₂ TaH ₃ ); Bis(methylcyclopentadienyl) tantalum trihydrogen ((CpMe) ₂ TaH ₃ ); derivatives thereof; and combinations thereof. 15. The method of claim 1, wherein the first and second metal layers each comprise tungsten, copper, or a combination thereof. 16. The method of claim 1, wherein the seed layer comprises a first seed layer deposited on the barrier layer and a second seed layer deposited on the first seed layer. 17. The method of claim 16, wherein the first seed layer comprises a copper alloy seed layer of copper and a metal selected from the group consisting of aluminum, magnesium, titanium, zirconium, tin, and combinations thereof, or wherein the first A seed layer includes a metal selected from the group consisting of aluminum, magnesium, titanium, zirconium, tin, and combinations thereof. 18. A method of forming metal interconnects on a substrate comprising: depositing a first metal layer on the substrate surface; Depositing a thickness of less than about 20 Angstroms on at least a portion of said first metal layer by alternately introducing one or more pulses of a titanium-containing compound, one or more pulses of a silicon-containing compound, and one or more pulses of a nitrogen-containing compound The titanium silicon nitride layer; depositing a double alloy seed layer; and A second metal layer is deposited on at least a portion of the double alloy seed layer. 19. A method of forming metal interconnects on a substrate, comprising: Depositing a double layer barrier having a thickness of less than about 20 Angstroms on at least a portion of the metal layer, the double layer barrier comprising: By alternately introducing one or more pulses of tantalum-containing compounds and one or more pulses of nitrogen-containing a first tantalum nitride layer deposited by pulses of the compound; and a second alpha-phase tantalum layer; depositing a double alloy seed layer; and A second metal layer is deposited on at least a portion of the double alloy seed layer. 20. A method of forming metal interconnects on a substrate, comprising: depositing a first metal layer on the substrate surface; depositing a barrier layer of tantalum nitride to a thickness of less than about 20 Angstroms on at least a portion of said first metal layer by alternately introducing one or more pulses of a tantalum-containing compound and one or more pulses of a nitrogen-containing compound; depositing a dual alloy seed layer comprising copper and a metal selected from the group consisting of aluminum, magnesium, titanium, zirconium, tin, and combinations thereof; and A second metal layer is deposited on at least a portion of the double alloy seed layer.

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