Summary of the invention
The invention provides a kind of contact hole formation method, can reduce the number of times of transfer substrate, then, the generation probability of reducing the number of rejects and seconds.
A kind of contact hole formation method provided by the invention comprises:
Order forms etching stop layer, dielectric layer and patterned resist layer in substrate;
With said patterned resist layer is mask, obtains patterned said dielectric layer;
Remove said patterned resist layer, when carrying out said removal operation, the pressure of reaction chamber is less than 20mT;
With patterned said dielectric layer is mask, obtains patterned said etching stop layer, to expose said substrate;
Wherein, the step that obtains patterned said dielectric layer, removes said patterned resist layer and obtain patterned said etching stop layer is carried out in same said reaction chamber, and does not all carry out cleaning operation between each step.
Alternatively, using plasma technology is carried out the operation that obtains patterned said dielectric layer, the said patterned resist layer of removal and obtain patterned said etching stop layer; Alternatively, the reacting gas of carrying out said removal operation is an oxygen; Alternatively, when carrying out said removal operation, the range of flow of said oxygen is 400sccm-800sccm; Alternatively, said cleaning operation comprises wet-cleaned; Alternatively, said cleaning operation also comprises plasma clean.
A kind of contact hole formation method provided by the invention comprises:
Order forms etching stop layer, dielectric layer and patterned resist layer in substrate;
With said patterned resist layer is mask, obtains patterned said dielectric layer;
Employing comprises the reacting gas of oxygen and removes said patterned resist layer, and the range of flow of said oxygen is 400sccm-800sccm;
With patterned said dielectric layer is mask, obtains patterned said etching stop layer, to expose said substrate;
Wherein, the step that obtains patterned said dielectric layer, removes said patterned resist layer and obtain patterned said etching stop layer is carried out in same reaction chamber, and does not all carry out cleaning operation between each step.
Alternatively, using plasma technology is carried out the operation that obtains patterned said dielectric layer, the said patterned resist layer of removal and obtain patterned said etching stop layer; Alternatively, said cleaning operation comprises wet-cleaned; Alternatively, said cleaning operation also comprises plasma clean.
Compared with prior art, technique scheme has the following advantages:
The contact hole formation method that technique scheme provides, through reducing the number of times that cleans, the number of times that the said substrate of minimizing is transferred between the differential responses chamber becomes possibility; Then; The pressure of reaction chamber or when reducing to remove said patterned resist layer through increasing the flow of the oxygen that adopts when removing said patterned resist layer; Promptly; Increase the vacuum degree of said reaction chamber, technological parameter that can be when regulate removing said patterned resist layer, minimum is reduced in the influence that will bring owing to the minimizing of wash number; In other words; Be beneficial to remove and originally use the byproduct of reaction that cleaning operation is removed, in addition, be easy to cause being attached to coming off of etch by-products on the said reaction chamber wall owing to increase the vacuum degree of said reaction chamber; Comprise the etching particle in the particle that comes off that produces; Technological parameter when regulate removing said patterned resist layer is beneficial to and detaches said etching particle, can make that to regulate the technological parameter operation minimum to the change that the critical dimension of said contact hole causes.
Embodiment
Although below with reference to accompanying drawings the present invention is described in more detail, wherein represented the preferred embodiments of the present invention, be to be understood that those skilled in the art can revise the present invention described here and still realize advantageous effects of the present invention.Therefore, following description is appreciated that broad to those skilled in the art, and not as limitation of the present invention.
For clear, whole characteristics of practical embodiments are not described.In following description, be not described in detail known function and structure, because they can make the present invention because unnecessary details and confusion.Will be understood that in the exploitation of any practical embodiments, must make a large amount of implementation details, for example, change into another embodiment by an embodiment according to relevant system or relevant commercial restriction to realize developer's specific objective.In addition, will be understood that this development possibly be complicated and time-consuming, but only be routine work to those skilled in the art.
In the following passage, with way of example the present invention is described more specifically with reference to accompanying drawing.Will be clearer according to description and claims advantage of the present invention and characteristic.What need explanation is, accompanying drawing all adopts the form of simplifying very much and all uses non-ratio accurately, only in order to convenient, the purpose of the aid illustration embodiment of the invention lucidly.
In the actual production, the processing procedure that forms said contact hole is usually directed to the etching operation of different material layer and suitable cleaning operation, and in the practice; From the consideration that reduces cross pollution; The etching operation of each said material layer is all carried out under single environment, that is, the etching operation of different material layer is carried out in different reaction chambers; Perhaps, utilize arbitrary said reaction chamber only a kind of material to be carried out etching operation.Thus; The processing procedure that causes forming said contact hole need comprise the repeatedly transfer between differential responses chamber operation; Said transfer operation both can betide so as between each reaction chamber of carrying out etching operation, also can betide so as between the reaction chamber and the reaction chamber so as to the execution cleaning operation of carrying out etching operation.
And said transfer process is prone to cause substrate contamination, increases the generation probability of waste product then, therefore, reduces number of times, the simplification flow process of the said substrate of transfer, becomes the subject matter that the present invention solves.
Inventor of the present invention proposes; Need the reason of repeatedly transfer to be in the traditional handicraft, the material different layer needs in different reaction chambers, to carry out etching operation, thus; How in same reaction chamber, to carry out etching operation and become the key that reduces the transfer number of times; In addition, if can reduce the number of times of carrying out cleaning operation, will further reduce the transfer number of times.
In the practice, the etching operation of different material layer is arranged in the same reaction chamber carries out simply, and/or, merely reduce the number of times of carrying out cleaning operation, be infeasible.This is because though this measure has reduced the generation probability of the waste product that increases often owing to transfer, but caused the deterioration of process conditions, and the process conditions that worsen will cause the generation of more waste products.
Particularly; As an example; In the traditional handicraft, the step that obtains patterned said dielectric layer is carried out in first reaction chamber and second reaction chamber respectively with the step of removing said patterned resist layer, carries out if only these two steps are arranged in the reaction chamber; To cause following situation: because said dielectric layer material is generally the oxide or the nitride of silicon, the etching gas of selecting for use is generally fluorocarbon gas (like CF
4And CH
2F
2Mist); Consider; What at first carry out is the step that obtains patterned said dielectric layer, that is, and and the step of the said dielectric layer of etching; After carrying out said etching operation, on the wall of reaction chamber, will be formed with polymer in the feasible practice with etching gas containing element (like fluorine, carbon); And in the step of the said patterned resist layer of proceeding of removal; Usually select for use oxygen as reacting gas; Said oxygen is after removing said resist layer; The said polymer that is formed on the reaction chamber wall of part will be peeled off, and the said polymer that peels off will provide have the etching gas containing element particle of (like fluorine, carbon), because what adopt is that plasma etch process is removed said patterned resist layer; Said particle will exert an influence to patterned said dielectric layer under the plasma etching condition, will cause the critical dimension of patterned said dielectric layer to change usually;
In addition, after removing said resist layer, will continue to carry out a cleaning operation usually, residual in order to remove resist, merely cancel said cleaning operation, will cause the deterioration of said resist layer removal effect, influence successive process.
Thus, inventor of the present invention has proposed a kind of contact hole formation method, and through reducing the number of times that cleans, the number of times that the said substrate of minimizing is transferred between the differential responses chamber becomes possibility; Then; The pressure of reaction chamber or when reducing to remove said patterned resist layer through increasing the flow of the oxygen that adopts when removing said patterned resist layer; Promptly; Increase the vacuum degree of said reaction chamber, technological parameter that can be when regulate removing said patterned resist layer, minimum is reduced in the influence that will bring owing to the minimizing of wash number; Then, the step order in same said reaction chamber that obtains patterned said dielectric layer, the said patterned resist layer of removal and obtain patterned said etching stop layer is carried out, reach the purpose that reduces the transfer number of times.
As the first embodiment of the present invention, the concrete steps that form contact hole comprise:
Step 81: order forms etching stop layer, dielectric layer and patterned resist layer in substrate;
Said substrate via go up the definition device active region at substrate (substrate) and accomplish shallow trench isolation from, form after forming grid structure and source region and drain region then.Said grid structure comprises the side wall and the gate oxide of grid, all around gate.Said substrate comprises but is not limited to comprise the silicon materials of element, and for example the silicon of monocrystalline, polycrystalline or non crystalline structure or SiGe (SiGe) also can be silicon-on-insulators (SOI).
Said etching stopping layer material can comprise silicon nitride.Said dielectric layer material can comprise phosphorosilicate glass (PSG).Said resist layer can be selected any anticorrosive additive material that can be applicable in the processing procedure for use.
In addition; In other embodiments of the invention, said substrate also can via definition device active region on the said substrate and accomplish shallow trench isolation from, then form grid structure and source region and drain region after, and then after depositing first interlayer dielectric layer; Continue to form ground floor through hole and groove; And fill said ground floor through hole and groove, subsequently, form behind the formation the first metal layer; Can expand ground, behind deposition N interlayer dielectric layer, continue to form N layer through hole and groove, and fill said N layer through hole and groove, subsequently, form the N metal level after, obtain said substrate.Obviously, the number N of the interlayer dielectric layer that comprises in the said substrate can be any natural number, and as 1,3,5,7 or 9 etc., the concrete number of the interlayer dielectric layer that comprises in the said substrate is confirmed according to product requirement.
Said dielectric layer material also can comprise advanced low-k materials, and said advanced low-k materials includes but not limited to black diamond (Black Diamond, a kind of BD) or among the coral.Said dielectric layer material also can comprise but be not limited to unadulterated silicon dioxide (SiO
2), Pyrex (BSG), boron-phosphorosilicate glass (BPSG), fluorine silex glass (FSG) or have a kind of or its combination in the advanced low-k materials.
Step 82: with said patterned resist layer is mask, obtains patterned said dielectric layer;
Particularly, but the using plasma etching technics obtains patterned said dielectric layer.The etching gas of selecting for use includes but not limited to octafluoroization three carbon (C
3F
8), octafluoroization four carbon (C
4F
8), hexafluoroization four carbon (C
4F
6), hexafluoroization two carbon (C
2F
6), Nitrogen trifluoride (NF
3), silicon fluoride (SiF
4) or hydrogen fluoride (HF) in a kind of and the combination.
Step 83: remove said patterned resist layer, when carrying out said removal operation, the pressure of reaction chamber is less than 20mT;
Using plasma technology is carried out the operation of removing said patterned resist layer; The reacting gas of carrying out said removal operation is an oxygen.The technical scheme that present embodiment provides and the difference of conventional art are: the pressure of reaction chamber has reduced.In conventional art; The pressure of reaction chamber is generally 30mT-40mT; The purpose that the pressure of present embodiment reaction chamber reduces to 20mT (even littler) is: the pressure of reaction chamber when reducing to remove said patterned resist layer; Increase the vacuum degree of said reaction chamber, be beneficial to and detach the particle that comprises the etching gas element that when removing said patterned resist layer, peels off, in other words; Be beneficial to remove and use the byproduct of reaction that cleaning operation is removed originally, minimum is reduced in the influence that can the minimizing owing to wash number be brought.
Because the pressure of reaction chamber when reducing to remove said patterned resist layer; Then; Increase the vacuum degree of said reaction chamber; Can save the cleaning operation behind the said patterned resist layer of above-mentioned removal, make the step that obtains patterned said dielectric layer, removes said patterned resist layer and obtain patterned said etching stop layer in same said reaction chamber, to carry out, reduce the transfer operation between different reaction chambers.
Step 84: with patterned said dielectric layer is mask, obtains patterned said etching stop layer, to expose said substrate; Wherein, the step that obtains patterned said dielectric layer, removes said patterned resist layer and obtain patterned said etching stop layer is carried out in same said reaction chamber, and does not all carry out cleaning operation between each step.
Using plasma technology is carried out and is obtained patterned said etching stop layer.Said cleaning operation comprises wet-cleaned and/or plasma clean.
In other embodiments of the invention, when carrying out said removal operation, the range of flow of said oxygen is 400sccm-800sccm, to strengthen the dynamics of removing said resist layer; Can after the pressure through reducing reaction chamber is with the vacuum degree that increases said reaction chamber, further increase the vacuum degree of said reaction chamber again through the mode that increases oxygen flow, be beneficial to the influence that the minimizing owing to wash number is brought and reduce to minimum.
As the second embodiment of the present invention, the concrete steps that form contact hole comprise:
Step 91: order forms etching stop layer, dielectric layer and patterned resist layer in substrate;
Step 92: with said patterned resist layer is mask, obtains patterned said dielectric layer;
Step 93: adopt the reacting gas that comprises oxygen to remove said patterned resist layer, the range of flow of said oxygen is 400sccm-800sccm;
Step 94: with patterned said dielectric layer is mask, obtains patterned said etching stop layer, to expose said substrate; Wherein, the step that obtains patterned said dielectric layer, removes said patterned resist layer and obtain patterned said etching stop layer is carried out in same reaction chamber, and does not all carry out cleaning operation between each step.
The main distinction of said second embodiment and first embodiment is: the concrete mode that will increase the vacuum degree of said reaction chamber is elected the flow that increases the oxygen that adopts when removing said patterned resist layer as.
Particularly, but using plasma technology carry out to obtain patterned said dielectric layer, remove said patterned resist layer and obtain the operation of patterned said etching stop layer; Said cleaning operation comprises wet-cleaned and/or plasma clean.
As shown in Figure 2; In the embodiments of the invention; After utilizing same reaction chamber 10 orders to carry out the operation that obtains patterned said dielectric layer, the said patterned resist layer of removal and obtain patterned said etching stop layer (corresponding step 82/92,83/93 and 84/94 respectively); The side is passed to another reaction chamber 11 with said substrate, to carry out cleaning operation step 89.
Through reducing the number of times that cleans; And; The pressure of reaction chamber or through increasing the flow of the oxygen that adopts when removing said patterned resist layer when reducing to remove said patterned resist layer increases the vacuum degree of said reaction chamber, can make to reduce the number of times that said substrate transfers become possibility between the differential responses chamber; Technological parameter that can be when regulate removing said patterned resist layer, minimum is reduced in the influence that will bring owing to the minimizing of wash number; In other words; Be beneficial to remove and originally use the byproduct of reaction that cleaning operation is removed, in addition, be easy to cause being attached to coming off of etch by-products on the said reaction chamber wall owing to increase the vacuum degree of said reaction chamber; Comprise particle in the particle that comes off that produces with etching gas element; Technological parameter when regulate removing said patterned resist layer is beneficial to and detaches said particle, can make that to regulate the technological parameter operation minimum to the change that the critical dimension of said contact hole causes.
What need stress is that not elsewhere specified step all can use conventional methods acquisition, and concrete technological parameter is confirmed according to product requirement and process conditions.
Although the present invention has been described and has enough described embodiment in detail although describe through the embodiment at this, the applicant does not hope by any way the scope of claims is limited on this details.Other to those skilled in the art advantage and improvement are conspicuous.Therefore, relative broad range the invention is not restricted to represent and the specific detail of describing, equipment and the method and the illustrative example of expression.Therefore, these details be can depart from and the spirit and the scope of the total inventive concept of applicant do not broken away from.