JPH0254926A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To produce a stable contact which causes no junction leak even upon application of heat in succeeding processes by subjecting TiN or TiW coated as a burrier metal to high speed thermal processing under a environment containing inert gas and oxygen gas. CONSTITUTION:At first, a Si substrate 101 is coated with an insulation film 102 and an opening is made therethrough. Then a burrier metal 103 is formed through sputtering. TiN or TiW is employed as the burrier metal. When TiN is employed, a halogen lamp annealing device is used for carrying out high speed thermal processing under an environment containing inert gas and oxygen gas. At this time, the temperature is brought higher than 700 deg.C. Oxygen gas flow is reduced as low as possible in order to prevent oxidation of TiN. Thereafter, a conductive wiring layer 105 is formed of Al alloy, for example, through sputtering. By such arrangement, junction leak does not occur even upon application of heat in the succeeding processes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a wiring conductive layer of a semiconductor device having a barrier metal.

[Conventional technology] Conventional technology is FJEE TRASAOT ONS
ON LKGTRON DKV OKS.

vOL, FD-54, NO, 3, +987 P.

As shown in No. 599, titanium nitride (hereinafter referred to as TiN) is formed as a barrier metal by reactive sputtering, and then A is applied in the same sputtering device without breaking the vacuum.
The idea was to form a t-wiring layer.

[Problems to be Solved by the Invention] In the above-mentioned conventional technology, as mentioned in the same document, when pure AA is used as the At wiring layer, the film thickness of TiN is 100 mm.
When the temperature is less than X, there is a problem that At diffuses into the 81 substrate due to heat treatment, causing bonding breakdown. In addition, if the TiN film thickness is increased, junction breakdown will not occur, but there is a problem in that the level difference in combination with the At wiring layer becomes higher, and the coverage of the upper protective insulating film and the interlayer insulating film of the At multilayer wiring decreases. .

Therefore, an object of the present invention is to provide a method for manufacturing a stable wiring layer that does not cause junction breakdown due to heat treatment.

[Means for Solving the Problems] The present invention provides a method for manufacturing a semiconductor device including a step of forming a barrier metal and a wiring conductive layer thereon, including a step of forming titanium nitride or titanium tungsten as the barrier metal; The method is characterized by including the steps of subjecting the titanium nitride or titanium tungsten to high-speed heat treatment in an atmosphere containing an inert gas and oxygen gas, and then forming a wiring conductive layer.

[Operation] According to the above structure of the present invention, T as a
After forming IN or titanium tungsten (hereinafter referred to as T1W), the TiN or TiW is subjected to high-speed heat treatment in an atmosphere containing an inert gas and oxygen gas, so that oxygen is trapped in the grain boundaries of the TiN or TiW. In addition, the TiN or TiW itself also becomes dense. The oxygen taken into the grain boundaries prevents At of the electrode metal from diffusing in TiN or in TiN. Also, TiN or T
As the iW itself becomes denser, A
t becomes difficult to diffuse.

[Embodiment] The detailed contents of the present invention will be explained below along with the drawings. FIG. 1 is a manufacturing process diagram in an embodiment of the present invention. First, an opening is provided in the insulating film 102 deposited on the 81 substrate 101. (Fig. 1 (α)) After that, the barrier metal 103
is formed by sputtering. The barrier metal material is TiN.

Tie, or silicide (MOSi2, WSi□,
TiN or Ttsiz) etc. are used, but recently TiN or T
iW is widely used. TiN is usually obtained by sputtering a pure T1 target in an atmosphere containing nitrogen while heating the substrate. In the present invention, TiN sputtered by the above method is used as an example of the barrier metal. (FIG. 1(b)) Next, the TiN is subjected to high-speed heat treatment in an atmosphere 104 containing inert gas and oxygen gas using a device capable of high-speed heat treatment such as a halogen lamp annealing device. If the temperature at this time is too low, it will not be effective, and it is usually 70°C.
A temperature of 0°C or higher is used. Furthermore, if the flow rate of oxygen gas is too large, TiN will be fermented, so it is better to keep the flow rate as low as possible. (FIG. 1(C)) Next, a wiring conductive layer 105 made of At alloy, etc.
is formed by sputtering. At this time, a bias sputtering method in which a bias is applied to the substrate may be used to improve step coverage. (FIG. 1(d)) FIG. 2 is a diagram showing the leakage characteristics of the N+/P- junction of the contact formed as described above. The sample has 10,000 N”/P- contacts connected in series, and +5V is applied to the electrode side.
When applying ? ! The flow value was measured. The horizontal axis of the graph is ′
The logarithm of the stream value, the vertical axis is the frequency distribution. After forming the conductive wire, heat treatment was performed at 450° C. for 1 hour. Traditional,
When TiN and At alloys are formed continuously in the same equipment, about 50% of them cause N+/P- junction leakage, as shown in Figure 1 (α). As a result of the high-speed heat treatment in a mixed gas of K and oxygen gas, there is no junction leakage as shown in FIG. 2(b), indicating good barrier properties. The sample according to the present invention was then subjected to heat treatment at 480°C for 30 minutes.
Although the above embodiment has been described using TiN as an example in which the number of junction leaks is only a few percent and there is a sufficient manufacturing margin, the same effect can be obtained with TiW. Like TiN, oxygen is incorporated into the grain boundaries, and the TIW itself is dense, so a stable contact that is less likely to cause junction leakage even when heat is applied can be obtained.

Further, as the inert gas, nitrogen gas, argon gas, etc. are used.

[Effects of the Invention] As described above, according to the present invention, TiN or TiW deposited as a barrier metal is subjected to high-speed heat treatment in an atmosphere containing inert gas and oxygen gas, so that heat can be removed in the subsequent process. This has the effect of providing a stable contact that does not cause junction leakage even when the contact is applied.

[Brief explanation of the drawing]

FIGS. 1(α) to (d) are manufacturing process diagrams showing one embodiment of the present invention. 101...S1 substrate 102...Insulating film 103...Barrier metal 104...Atmosphere 105 containing inert gas and oxygen gas - Wiring conductive layer FIG. 2 (α) and (h) are graphs showing the effects of one embodiment of the present invention. Fig. 2 (α) ... Frequency distribution of junction leakage current of contacts according to the conventional method Fig. 2 (b) ... Frequency distribution of junction leakage current of contacts according to the present invention Jl'J [ -10 Insui 9

Claims (1)

[Claims] A method for manufacturing a semiconductor device including a step of forming a barrier metal and a wiring conductive layer thereon, a step of forming titanium nitride or titanium tungsten as the barrier metal, and a step of forming the titanium nitride or titanium tungsten with an inert gas and an oxygen gas. 1. A method for manufacturing a semiconductor device, comprising the steps of performing high-speed heat treatment in an atmosphere containing the following: and thereafter forming a wiring conductive layer.