• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.37-40
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• 1999

For the first time, charge trapping nonvolatile semiconductor memories with the deoxidized oxynitride gate dielectric is proposed and demonstrated. Gate dielectric wit thickness of less than 1 nm have been grown by postnitridation of pregrown thermal silicon oxides in NO ambient and then reoxidation. The nitrogen distribution and chemical state due to NO anneal/reoxidation were investigated by M-SIMS, TOF-SIMS, AES depth profiles. When the NO anneal oxynitride film was reoxidized on the nitride film, the nitrogen at initial oxide interface not only moved toward initial oxide interface, but also diffused through the newly formed tunnel oxide by exchange for oxygen. The results of reoxidized oxynitride(ONO) film analysis exhibits that it is made up of SiO$_2$(blocking oxide)/N-rich SiON interface/Si-rich SiON(nitrogen diffused tunnel oxide)/Si substrate. In addition, the SiON and the S1$_2$NO Phase is distributed mainly near the tunnel oxide, and SiN phase is distributed mainly at tunnel oxide/Si substrate interface.

• E2M - 전기 전자와 첨단 소재
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• 제7권1호
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• pp.25-31
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• 1994

Properties of oxynitride films reoxidized by $N_2{O}$ gas after thermal oxidation and $N_2{O}$ oxide films directly oxidized by using $N_2{O}$ gas on the bare silicon wafer have been studied. From the AES analysis, nitrogen pile-up at the interface of Si/oxynitride and Si/$N_2{O}$ oxide has observed. $N_2{O}$ oxide and oxynitride films have the self-limited characteristics. Therefore, it will be possible to obtain ultra-thin films. Nitrogen pile-up at the interfaces of Si/oxynitride and Si/$N_2{O}$ oxide strengthens film structure and improves dielectric reliability. Although fixed charge densities and interface trap densities of N20 oxide and oxynitride films have somewhat higher than those of thermal $SiO_2{O}$, $N_2{O}$ oxide and oxynitride films showed improved I-V characteristics and constant current stress.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 춘계학술대회 논문집
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• pp.39-43
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• 1993

Electricial characteristics of gate dielectrics prepared by reoxidation of thermal $SiO_2$ in nitrous oxide gas have been investigated. 10 and 19nm-thick oxides were reoxidized at temperatures of $900-1000^{\circ}C$ for 10-60 min in $N_2O$ ambient. As reoxidation proceeds, it is shown that nitrogen concentration at $Si/SiO_2$ interface increases gradually through the AES analysis. Nitrogen pile-up at $Si/SiO_2$ interface acts as a oxidant diffusion barrier that reduces the oxidation rate significantly. And it not only strengthen oxynitride structure at the interface but improve the gate dielectric qualities. Reliabilities of oxynitride films are conformed by the breakdown distributions and constant current stress technique. Therefore, the oxynitride films made by this process show a good promise for future ULSI applications.

• 한국결정성장학회지
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• 제12권6호
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• pp.304-310
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• 2002

실리콘 기판 위의 초기 산화막을 NO 열처리 및 재산화 공정방법으로 성장한 재산화된 질화산화막을 게이트 유전막으로 사용한 새로운 전하트랠형 기억소자로의 응용가능성과 계면트랩특성을 조사하였다. 0.35$\mu$m CMOS 공정기술을 사용하여 게이트 유전막은 초기산화막을 $800^{\circ}C$에서 습식 산화하였다 전하트랩영역인 질화막 층을 형성하기 위해 $800^{\circ}C$에서 30분간 NO 열처리를 한 후 터널 산화막을 만들기 위해 $850^{\circ}C$에서 습식 산화방법으로 재산화하였다. 프로그램은 11 V, 500$\mu$s으로 소거는 -l3 V, 1 ms의 조건에서 프로그래밍이 가능하였으며, 최대 기억창은 2.28 V이었다. 또한 11 V, 1 ms와 -l3 V, 1 ms로 프로그램과 소거시 각각 20년 이상과 28시간의 기억유지특성을 보였으며 $3 \times 10^3$회 정도의 전기적 내구성을 나타내었다. 단일접합 전하펌핑 방법으로 소자의 계면트랩 밀도와 기억트랩 밀도의 공간적 분포를 구하였다. 초기상태에서 채널 중심 부근의 계면트랩 및 기억트랩 밀도는 각각 $4.5 \times 10^{10}/{cm}^2$ 와 $3.7\times 10^{1R}/{cm}^3$ 이었다. $1 \times 10^3$프로그램/소거 반복 후, 계면트랩은 $2.3\times 10^{12}/{cm}^2$으로 증가하였으며, 기억트랩에 기억된 전하량은 감소하였다.