CN102154650B - Thick aluminum etching method during producing bipolar integrated circuit - Google Patents
Thick aluminum etching method during producing bipolar integrated circuit Download PDFInfo
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Abstract
The invention relates to a thick aluminum etching method during producing a bipolar integrated circuit. The method is characterized by comprising the following steps of: 1) preetching to remove an oxide and an ARC (arc) layer on the surface of a metal layer; 2) etching 1/2-2/3 thickness of an aluminum medium layer; and 3) etching the residual 1/3-1/2 thickness of the aluminum medium layer, and removing a residual material layer. After the method is used, the requirement and the dependence for setting a single-step main etching technology can be reduced, and the side effects caused by the defects of a dry etching load effect and the like can be effectively reduced, so that a better etching effect can be obtained.
Description
Technical field
The present invention relates to the thick aluminium lithographic method in a kind of bipolar integrated circuit making processes.
Background technology
In present semiconductor fabrication industry, aluminium is the most general interconnecting metal material.For the electromigration that reduces aluminium with form the problem such as hillock, aluminum bronze, Al-Si-Cu alloy material are applied to semiconductor fabrication process more and more, but its main medium or aluminium, and copper and silicon are only as a small amount of miserable assorted.In traditional metallization processes, aluminium or aluminum alloy materials are coated on the medium layer, then form metal connecting line by photoetching and dried the quarter.To traditional metallization processes, metal etch is an important sport technique segment, and the quality of etching effect directly has influence on performance, the quality of whole unicircuit.Aluminium is to be deposited on one of the thickest film on the silicon chip.For example, have the metal level of welding zone, its thickness can surpass 2.0 μ m.Find in the FAB production practice, metal medium thickness is thicker, and also higher to the difficulty requirement of etching technics, especially metal medium thickness surpasses in the situation of 2.0 μ m obvious all the more.Remover apparatus aspect factor, with regard to process aspect, the thicker required etching time of metal medium is also longer, also thereupon aggravation of the caused ill effect reaction of the drawbacks such as the load effect of dry etching and proximity effect.
Traditional aluminium etch step can be divided into: the pre-etching of 1, removing natural oxidizing layer; 2, etching ARC layer; 3, the main etching of etching aluminium (Main Etch); 4, remove the over etching (Over Etch) of residue; 5, the etching on blocking layer; 6, be the selective removal of Erosion prevention residue; 7, remove photoresist material.Wherein the main etching step is the core technology link, and the parameters such as its speed, homogeneity, selection ratio, Etching profile farthest have influence on whole etching effect, are vital so obtain a desirable main etching step.
Traditional main etching step is to utilize plasma etching machine, one step (comprising the parameters such as RF, DC bias, gas flow, etching cavity pressure and etching time) etch step and the method by end point determination are set realize whole main etching step process, and then the etching difference that a step over etching step removes residue and remedies the subregion is set.This lithographic method has all focused on the main etching step to most of etching pressure, has also naturally improved the requirement to the main etching process, and become depends on him very much.In actual FAB production process, find, in the situation that the aluminium film thickness is thicker, especially in the situation greater than 2.0 μ m, it is unusual difficult seeking a desirable main etching process setting of step, usually can attend to one thing and lose sight of another, for obtaining desirable etch rate, but can not get high selection ratio; But for obtaining high selection than not obtaining good etching homogeneity.In order to reduce the method that damage also can take dry etching to be combined with wet etching usually to layer dielectric, namely remove the aluminium lamination of most of thickness with dry method, use again the rotten net surplus aluminium lamination of wet method.Although this method can guarantee the loss amount of layer dielectric, it also comes with some shortcomings: such as the wet etching isotropy aluminum strip is attenuated; Processing step is loaded down with trivial details, and easily brings out erosion, and post-etching etc. are unusual, and impact is produced.
Summary of the invention
The object of the present invention is to provide the thick aluminium lithographic method in a kind of bipolar integrated circuit making processes, this method can reduce requirement and the dependency that single step main etching technique is arranged, effectively alleviate the negative impact that the drawbacks such as dry etching load effect are brought, thereby obtain better etching effect.
Technical program of the present invention lies in: the thick aluminium lithographic method in a kind of bipolar integrated circuit making processes is characterized in that: carry out according to the following steps: 1) pre-etching, to remove metal layer surface oxidation thing and ARC layer; 2) the aluminium medium layer of etching 1/2 ~ 2/3 thickness; 3) the aluminium medium layer of etching residue 1/3 ~ 1/2 thickness, and remove the residue layer.
Described step 2) average etching rate to the aluminium medium layer in is 700 ~ 1000
/ min, etching homogeneity are 1 ~ 5%, Al/SiO
2Select than being 8.0 ~ 10.0.
Described step 2) etching cavity pressure is 20 ~ 50mTorr in, and radio frequency is 2000W to the maximum, and volts DS is 180 ~ 220V, BCl
3Flow be 80 ~ 90SCCM, Cl
2Flow be 20 ~ 40SCCM, CHF
3Flow be 10 ~ 20SCCM, etching time is 15 ~ 25min.
Average etching rate to the aluminium medium layer in the described step 3) is 1200 ~ 1500
/ min, etching homogeneity are 5.5 ~ 8.0%, Al/SiO
2Select than being 15 ~ 20.
Etching cavity pressure is 20 ~ 50mTorr in the described step 3), and radio frequency is 2000W to the maximum, and volts DS is 180 ~ 220V, BCl
3Flow be 90 ~ 110SCCM, Cl
2Flow be 40 ~ 60SCCM, CHF
3Flow be 10 ~ 20SCCM, etching time is for being no more than 25min.
The maximum slope α of the Etching profile that forms described step 2) is 87 ~ 89 °, and the maximum slope β of the Etching profile that forms in the described step 3) is 84 ~ 87 °.
Etching cavity pressure is 20 ~ 50mTorr in the described step 1), and radio frequency is 2000W to the maximum, and volts DS is 250 ~ 270V, BCl
3Flow be 80 ~ 110SCCM, Cl
2Flow be 10 ~ 20SCCM, CHF
3Flow be 10 ~ 20SCCM, etching time is for being no more than 2 ~ 5min.
Before described step 1) was carried out, first at aluminium medium layer surface deposition one deck 2.0 ~ 3.5 μ m fine aluminium or Al-Si-Cu alloys, and photoetching thereon formed required figure and screens as etching.
After etching finishes, remove photoresist material, form metal connection structure.
The invention has the advantages that: the difference of the present invention and traditional lithographic method maximum is, traditional aluminium etching is to utilize the main etching step to finish the etching of most aluminium laminations in the mode of single step etching, remove residue and the process that remedies the etching difference of subregion with a step over etching step again, and the present invention is the processing step that utilizes two step particular requirements, finish the etching of aluminium lamination interimly and remove the process of etch residue, there is not the differentiation of proper main etching and over etching step in it.In bipolar integrated circuit is made in the technique category of thick aluminium etching, superiority of the present invention is especially remarkable, core theory thought of the present invention can be applied even more extensively the lithographic technique field in other medium layers, the etching of media such as thick silicon-dioxide, silicon nitride.
Description of drawings
Fig. 1 is the structural representation that the present invention finishes the front road of metallization technique.
Fig. 2 is that the present invention finishes the structural representation that photoetching forms etching shielding.
Fig. 3 is the structural representation that the present invention finishes pre-etch step.
Fig. 4 is completing steps 2 of the present invention) after structural representation.
Fig. 5 is completing steps 3 of the present invention) after structural representation.
Fig. 6 is step 2 of the present invention) and the maximum slope contrast schematic diagram of the Etching profile that forms of step 3).
Fig. 7 is the final structural representation that forms of the present invention.
Shown in the number in the figure: I, substrate dielectric II, aluminium medium layer III, Al-Si-Cu alloy layer.
Embodiment
As shown in Figures 1 and 2, first at aluminium medium layer surface deposition one deck 2.0 ~ 3.5 μ m fine aluminium or Al-Si-Cu alloys, as shown in the figure III layer, and photoetching thereon forms required figure and screens as etching.
Post bake (Hard Bake) before carving, its meaning are to reduce liquid solvent content in the photoresist material, strengthen the adhesivity of photoresist material and metallic dielectric layer, are conducive to do carve obtain more preferably etching effect.
As shown in Figure 3, then carry out the aluminium medium layer, as shown in the figure the II layer, etching, 1), pre-etching, to remove metal layer surface oxidation thing and ARC layer, this step is mainly utilized B ion physical bombardment effect, removal is grown in zone of oxidation and the ARC layer of metal surface, avoid metal etch to be obstructed, etching cavity pressure is 20 ~ 50mTorr in the described step 1), and radio frequency is 2000W to the maximum, volts DS is 250 ~ 270V, BCl
3Flow be 80 ~ 110SCCM, Cl
2Flow be 10 ~ 20SCCM, CHF
3Flow be 10 ~ 20SCCM, etching time is for being no more than 2 ~ 5min.
As shown in Figure 4,2), the aluminium medium layer of etching 1/2 ~ 2/3 thickness, described step 2) in be 700 ~ 1000 to the average etching rate of aluminium medium layer
/ min, etching homogeneity are 1 ~ 5%, Al/SiO
2Select than being 8.0 ~ 10.0 described step 2) middle etching cavity pressure is 20 ~ 50mTorr, and radio frequency is 2000W to the maximum, and volts DS is 180 ~ 220V, BCl
3Flow be 80 ~ 90SCCM, Cl
2Flow be 20 ~ 40SCCM, CHF
3Flow be 10 ~ 20SCCM, etching time is 15 ~ 25min.
As shown in Figure 5,3), the aluminium medium layer of etching residue 1/3 ~ 1/2 thickness, and remove the residue layer, the average etching rate to the aluminium medium layer in the described step 3) is 1200 ~ 1500
/ min, etching homogeneity are 5.5 ~ 8.0%, Al/SiO
2Select than being 15 ~ 20, etching cavity pressure is 20 ~ 50mTorr in the described step 3), and radio frequency is 2000W to the maximum, and volts DS is 180 ~ 220V, BCl
3Flow be 90 ~ 110SCCM, Cl
2Flow be 40 ~ 60SCCM, CHF
3Flow be 10 ~ 20SCCM, etching time is for being no more than 25min.
Be set with the etch step of end point determination one step, the mode of taking manually to stop the etching program is finished the process of the removal of the metallic dielectric layer of remaining 1/3 to 1/2 thickness of second step etching and etch residue rapidly, and guarantees that over etching in this process is crossed substrate under the metal level and carve damage and reach processing requirement
The maximum slope α of the Etching profile that forms described step 2) is 87 ~ 89 °, and the maximum slope β of the Etching profile that forms in the described step 3) is 84 ~ 87 °.
Step 2) parameter arranges the relative the first step and has improved Cl in
2And BCl
3Gas flow, in the etching of aluminium, chemical reaction is being dominated the carrying out of etching, therefore improves Cl
2Flow has just increased muriatic content, also just can accelerate the etch rate of aluminium; Adding a small amount of silicon and copper is common aluminum alloy materials in aluminium, so the removal of silicon and copper also becomes the factor of the required consideration of aluminium etching.If both fail to remove, can bring the Micromasking phenomenon, namely little Screen theory can directly be finished in chloride gas electricity slurry for the etching of silicon, and SiCl
4Volatility is fine, therefore can not bring very burden.Yet the removal of copper is difficulty relatively, because CuCl
2Vapour pressure is very low, and is not volatile, so need high-octane ionic bombardment to remove copper atom, the B ion then is the ace spiker of physical action, improves BCl
3The flow main purpose also is for this reason.Be accompanied by the variation of gas flow, etch topography is affected by it also can, can realize control by fine setting etching pressure etc.
Step 2) compare with step 3): etching homogeneity step 2) is better, and the speed of step 3) is faster and select than better.
The aluminium Etching profile slope difference that obtains is no more than 10 °, and mathematical way is expressed as Etching profile slope difference △=∠ α-∠ β, and △≤10 ° are as shown in Figure 6, therefore very little on the covering impact of rear track media layer.
As shown in Figure 7, after etching finishes, utilize plasma degumming machine to remove photoresist material, finally finish the whole process of metal medium etching, form metal connection structure.
In actual FAB production process; because affected by various objective factors; often can not guarantee in time to remove photoresist material behind every batch of silicon chip erosion; this may bring the problems such as metal level is etched, and is used for effectively controlling metal level and is etched so usually can increase some steps before removing the photoresist material step.For example: before chip shifts out cavity, with fluorochemical (CF
4, CHF
3Deng) the surface processing of electricity slurry do, residual Cl is replaced into F, form AlF
3, form one layer of polymeric on aluminium surface, with contacting of isolation Al and Cl; Perhaps after shifting out cavity, chip imposes a large amount of deionized water rinsing etc., because it affects without substantivity the present invention, so do not do detailed discussion.
The difference of the present invention and traditional lithographic method maximum is, traditional aluminium etching is to utilize the main etching step to finish the etching of most aluminium laminations in the mode of single step etching, remove residue and the process that remedies the etching difference of subregion with a step over etching step again, and the present invention is the processing step that utilizes two step particular requirements, finish the etching of aluminium lamination interimly and remove the process of etch residue, there is not the differentiation of proper main etching and over etching step in it, in bipolar integrated circuit is made in the technique category of thick aluminium etching, superiority of the present invention is especially remarkable, core theory thought of the present invention can be applied even more extensively the lithographic technique field in other medium layers, for example thick silicon-dioxide in fact, the etching of the media such as silicon nitride.
The above only is preferred embodiment of the present invention, and all equalizations of doing according to the present patent application claim change and modify, and all should belong to covering scope of the present invention.
Claims (5)
1. the thick aluminium lithographic method in the bipolar integrated circuit making processes is characterized in that: carry out according to the following steps:
1) pre-etching is to remove metal layer surface oxidation thing and ARC layer;
2) the aluminium medium layer of etching 1/2 ~ 2/3 thickness;
3) the aluminium medium layer of etching residue 1/3 ~ 1/2 thickness, and remove the residue layer;
Described step 2) average etching rate to the aluminium medium layer in is 700 ~ 1000
/ min, etching homogeneity are 1 ~ 5%, Al/SiO
2Select than being 8.0 ~ 10.0;
Described step 2) etching cavity pressure is 20 ~ 50mTorr in, and radio frequency is 2000W to the maximum, and volts DS is 180 ~ 220V, BCl
3Flow be 80 ~ 90SCCM, Cl
2Flow be 20 ~ 40SCCM, CHF
3Flow be 10 ~ 20SCCM, etching time is 15 ~ 25min.
Average etching rate to the aluminium medium layer in the described step 3) is 1200 ~ 1500
/ min, etching homogeneity are 5.5 ~ 8.0%, Al/SiO
2Select than being 15 ~ 20;
Etching cavity pressure is 20 ~ 50mTorr in the described step 3), and radio frequency is 2000W to the maximum, and volts DS is 180 ~ 220V, BCl
3Flow be 90 ~ 110SCCM, Cl
2Flow be 40 ~ 60SCCM, CHF
3Flow be 10 ~ 20SCCM, etching time is for being no more than 25min.
2. the thick aluminium lithographic method in a kind of bipolar integrated circuit making processes according to claim 1, it is characterized in that: the maximum slope α of the Etching profile that forms described step 2) is 87 ~ 89 °, and the maximum slope β of the Etching profile that forms in the described step 3) is 84 ~ 87 °.
3. the thick aluminium lithographic method in a kind of bipolar integrated circuit making processes according to claim 1, it is characterized in that: etching cavity pressure is 20 ~ 50mTorr in the described step 1), and radio frequency is 2000W to the maximum, volts DS is 250 ~ 270V, BCl
3Flow be 80 ~ 110SCCM, Cl
2Flow be 10 ~ 20SCCM, CHF
3Flow be 10 ~ 20SCCM, etching time is for being no more than 2 ~ 5min.
4. the thick aluminium lithographic method in a kind of bipolar integrated circuit making processes according to claim 1, it is characterized in that: before described step 1) is carried out, first at aluminium medium layer surface deposition one deck 2.0 ~ 3.5 μ m fine aluminium or Al-Si-Cu alloys, and photoetching thereon forms required figure and screens as etching.
5. the thick aluminium lithographic method in a kind of bipolar integrated circuit making processes according to claim 4 is characterized in that: after etching finishes, remove photoresist material, form metal connection structure.
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| CN103050398B (en) * | 2011-10-14 | 2016-01-20 | 无锡华润上华半导体有限公司 | A kind of thick semiconductor metal structure manufacture method |
| CN105225923B (en) * | 2014-05-29 | 2019-11-26 | 上海矽睿科技有限公司 | The preprocess method and bonding method of aluminum material for bonding |
| CN107346732B (en) * | 2016-05-04 | 2020-10-16 | 北大方正集团有限公司 | Method for preparing metal connecting wire of integrated circuit |
| CN110616431B (en) * | 2018-06-20 | 2021-11-16 | 深圳先进技术研究院 | Surface treatment method for battery tab |
| CN113067558A (en) * | 2021-03-03 | 2021-07-02 | 上海萍生微电子科技有限公司 | Diversified etching method for surface acoustic wave filter chip |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020179569A1 (en) * | 2001-03-30 | 2002-12-05 | Duane Outka | Method of reducing aluminum fluoride deposits in plasma etch reactor |
| CN1551294A (en) * | 2003-05-14 | 2004-12-01 | Ӧ�ò��Ϲ�˾ | Method for etching an aluminum layer using an amorphous carbon mask |
| CN1778993A (en) * | 2004-11-19 | 2006-05-31 | 中国科学院微电子研究所 | High-precision sculpturing method of thick aluminium by dry method |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20020179569A1 (en) * | 2001-03-30 | 2002-12-05 | Duane Outka | Method of reducing aluminum fluoride deposits in plasma etch reactor |
| CN1551294A (en) * | 2003-05-14 | 2004-12-01 | Ӧ�ò��Ϲ�˾ | Method for etching an aluminum layer using an amorphous carbon mask |
| CN1778993A (en) * | 2004-11-19 | 2006-05-31 | 中国科学院微电子研究所 | High-precision sculpturing method of thick aluminium by dry method |
Non-Patent Citations (1)
| Title |
|---|
| 杨荣等.改善硅基螺旋电感品质因数的厚铝膜干法刻蚀.《固体电子学研究与进展》.2006,第26卷(第3期),389-393. * |
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