US6316349B1
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Method for forming contacts of semiconductor devices
Assignee: SK Hynix Inc
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Filing: 1999-11-10
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Granted: 2001-11-13
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Expires: 2019-11-10
Abstract
Abstract Disclosed is a method for forming contacts of a semiconductor device. In accordance with the invention, an oxidized silicon-rich nitride film is used as an etch barrier film for a self-aligned contact (SAC) process. Accordingly, the oxidized silicon-rich nitride film exhibits less stress, as compared to an LPCVD nitride film, thereby being capable of avoiding a degradation in the characteristics of the devices finally produced or distortion of the wafer used. There is no formation of cracks occurring in the nitride film during a subsequent thermal process. It is also unnecessary to conduct an additional reflection preventing process. Accordingly, the entire process is simplified. It is also possible to improve a decrease in the operating speed of the devices due to a parasitic capacitance existing among conductive lines because the oxidized silicon-rich nitride film has a low dielectric constant, as compared to nitride films. No damage occurs in the oxidized silicon-rich nitride film, so that it is possible to prevent the substrate from being damaged.
Inventors
- 👤 Jeong Ho Kim
- 👤 Jae Ok Ryu
- 👤 Ja Chun Ku
- 👤 Jin Woong Kim
- 👤 Si Bum Kim
- 👤 Su Jin Oh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:23
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6921; H10P14/6922; H10P14/6927; H10D; H10D64/00; H10D64/01; H10D64/021; H10P14/65; H10P14/6516; H10P14/6518; H10P14/6519; H10P14/6522; H10P14/6529; H10P14/6532; H10P14/66; H10P14/668; H10P14/6681; H10P14/6682; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/069; H10W20/071; H10W20/074; H10W20/077; H10P14/63; H10P14/6326; H10P14/6328; H10P14/6334; H10P14/6336; H10P14/662; H10P14/69215; H10P14/694; H10P14/6943; H10P14/69433; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
124 words
A method for forming contacts of a semiconductor device comprising the steps of: forming a conductive layer over a semiconductor substrate, and forming, over the conductive layer, a hard mask comprised of a first oxidized silicon-rich nitride film containing amorphous or polycrystalline silicon in amount of 5 to 70%; processing the first oxidized silicon-rich nitride film using plasma, thereby forming an oxide film over the first oxidized silicon-rich nitride film; patterning the hard mask and the conductive layer, thereby forming a hard mask pattern and conductive lines; and forming, on side walls of the hard mask pattern and side walls of the conductive lines, spacers comprised of a second oxidized silicon-rich nitride film containing amorphous or polycrystalline silicon in amount of 5 to 70%.
Claim 2
Independent Claim
124 words
A method for forming contacts of a semiconductor device comprising the steps of: forming a conductive layer over a semiconductor substrate, and forming, over the conductive layer, a hard mask comprised of a first oxidized silicon-rich nitride film containing amorphous or polycrystalline silicon in amount of 5 to 70%; processing the first oxidized silicon-rich nitride film using plasma, thereby forming an oxide film over the first oxidized silicon-rich nitride film; patterning the hard mask and the conductive layer, thereby forming a hard mask pattern and conductive lines; and forming, on side walls of the hard mask pattern and side walls of the conductive lines, spacers comprised of a second oxidized silicon-rich nitride film containing amorphous or polycrystalline silicon in amount of 5 to 70%.
Claim 3
Dependent Claim
46 words
The method in accordance with claim 1 , wherein the first oxidized silicon-rich nitride film is formed in accordance with an in-situ process so that it exhibits a low silicon content at a lower portion thereof and a high silicon content at an upper portion thereof.
Claim 4
Dependent Claim
54 words
The method in accordance with claim 2 , wherein the first oxidized silicon-rich nitride film essentially consists of silicon nitride (Si 3 N 4 ) and silicon oxide (SiO 2 ) along with the amorphous or polycrystalline silicon while having a silicon nitride (Si 3 N 4 ) content ranging from 10% to 90%.
Claim 5
Dependent Claim
44 words
The method in accordance with claim 1 , wherein the first and second oxidized silicon-rich nitride films are formed in accordance with a plasma enhanced chemical vapor deposition (PECVD) process using a radio frequency source of 13.56 MHz, or 100 Hz to 1 MHz.
Claim 6
Dependent Claim
46 words
The method in accordance with claim 4 , wherein the PECVD process is conducted at a pressure of 0.5 to 20 Torr while applying a substrate bias by use of a plasma generating power of 0 to 2 KW to obtain an increased thin film density.
Claim 7
Dependent Claim
58 words
The method in accordance with claim 4 , wherein the PECVD process uses a deposition gas mixture containing SiH 4 in amount of 0 to 500 sccm, N 2 O in amount of 0 to 5,000 sccm, and N 2 in amount of 0 to 50,000 sccm while being diluted by inert gas of He, Ne, or Ar.
Claim 8
Dependent Claim
38 words
The method in accordance with claim 1 , wherein the first and second oxidized silicon-rich nitride films are formed in accordance with a plasma enhanced chemical vapor deposition (PECVD) process using a superhigh frequency source of 2.45 GHz.
Claim 9
Dependent Claim
46 words
The method in accordance with claim 7 , wherein the PECVD process is conducted at a pressure of 0.002 to 100 Torr while applying a substrate bias by use of a plasma generating power of 0 to 5 KW to obtain an increased thin film density.
Claim 10
Dependent Claim
58 words
The method in accordance with claim 7 , wherein the PECVD process uses a deposition gas mixture containing SiH 4 in amount of 0 to 500 sccm, N 2 O in amount of 0 to 5,000 sccm, and N 2 in amount of 0 to 50,000 sccm while being diluted by inert gas of He, Ne, or Ar.
Claim 11
Dependent Claim
89 words
The method in accordance with claim 1 , wherein the step of processing the first oxidized silicon-rich nitride film using plasma is carried out in accordance with an in-situ process in a reaction chamber under the condition using a reaction chamber pressure of 0.1 to 10 Torr, a radio-frequency application power of 0 to 5,000 KW, a substrate temperature of 100 to 500° C., and an electrode space of 100 to 1,000 mils while using N 2 O or O 2 gas in amount of 100 to 10,000 sccm.
Claim 12
Independent Claim
123 words
A method for forming contacts of a semiconductor device comprising the steps of: sequentially laminating, over a semiconductor substrate, a conductive layer, a first oxidized silicon nitride film, and a first oxidized silicon-rich nitride film, and patterning them, thereby forming conductive lines; forming, on side walls of the conductive lines, spacers each having a laminated structure including a second oxidized silicon nitride film and a second oxidized silicon-rich nitride film, respectively; forming an interlayer insulating film over the entire upper surface of the resulting structure to planarize the upper surface of the resulting structure; and forming contact holes in a self-aligned fashion in accordance with a self-aligned contact etch process while exposing desired portions of the semiconductor substrate through the contact holes, respectively.
Claim 13
Independent Claim
123 words
A method for forming contacts of a semiconductor device comprising the steps of: sequentially laminating, over a semiconductor substrate, a conductive layer, a first oxidized silicon nitride film, and a first oxidized silicon-rich nitride film, and patterning them, thereby forming conductive lines; forming, on side walls of the conductive lines, spacers each having a laminated structure including a second oxidized silicon nitride film and a second oxidized silicon-rich nitride film, respectively; forming an interlayer insulating film over the entire upper surface of the resulting structure to planarize the upper surface of the resulting structure; and forming contact holes in a self-aligned fashion in accordance with a self-aligned contact etch process while exposing desired portions of the semiconductor substrate through the contact holes, respectively.
Claim 14
Dependent Claim
35 words
The method in accordance with claim 11 , wherein the first and second oxidized silicon nitride films are formed in an in-situ fashion with respect to the first and second oxidized silicon-rich nitride films, respectively.
Claim 15
Dependent Claim
43 words
The method in accordance with claim 11 , wherein the self-aligned contact etch process is conducted using C—F-based plasma capable of providing a sufficient etch selectivity difference between the interlayer insulating film and each of the first and second oxidized silicon-rich nitride film.
Claim 16
Dependent Claim
35 words
The method in accordance with claim 13 , wherein the self-aligned contact etch process is conducted while additionally using inert gas of argon or helium to achieve an improvement in stability of the etch process.
Claim 17
Dependent Claim
31 words
The method in accordance with claim 11 , wherein the self-aligned contact etch process is conducted using carbon-rich fluorine gas of C 3 F 8 or C 5 F 8 .
Claim 18
Dependent Claim
34 words
The method in accordance with claim 13 , wherein the self-aligned contact etch process is conducted while additionally using C—H—F-based gas to avoid an etch stopping phenomenon occurring due to a production of polymer.
Claim 19
Dependent Claim
23 words
The method in accordance with claim 11 , wherein the first and second oxidized silicon nitride films are replaced with oxide films, respectively.
References Cited (Backward Citations)
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