초임계 이산화탄소를 이용한 웨이퍼의 건식 식각에서 알콜 첨가제의 효과

김도훈; 장명재; 임권택; Do Hoon Kim; Myoung Jae Jang; Kwon Taek Lim

Clean Technology, Vol.18, No.3, 280-286, September, 2012

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초임계 이산화탄소를 이용한 웨이퍼의 건식 식각에서 알콜 첨가제의 효과

Effect of Alcohols on the Dry Etching of Sacrificial SiO2 in Supercritical CO2

김도훈, 장명재, 임권택 ^†

부경대학교 이미지시스템 공학과, 608-739 부산광역시 남구 대연동 566-1

Do Hoon Kim, Myoung Jae Jang, and Kwon Taek Lim^†

Department of Image Science & Engineering, Pukyong National University, 566-1 Daeyeon-dong, Nam-gu, Busan 608-737, Korea

E-mail:

초록

초임계 이산화탄소를 이용하여 희생 SiO2층에 대한 건식 식각 실험을 진행하였다. HF/pyridine(HF/py) 식각액과 알콜 첨가제를 사용하여 이중 챔버 시스템 방식으로 boron phosphor silica glass (BPSG), tetraethyl orthosilicate (TEOS), thermal SiO2와 Si-nitride (SiN)의 박막 층에 대한 식각 성능을 조사하였다. 메탄올의 첨가에 의하여 실리카 희생막에 대한 HF/py의 식각률이 높아지는 것을 확인할 수 있었다. BPSG를 제외하고는 메탄올이 가장 높은 식각률을 보여줬지만, BPSG의 SiN에 대한 식각 선택비는 이소프로판올이 가장 높았다. HF/py/MeOH 계의 건식 식각반응에서 반응 온도에 따라서 박막별 식각률이 증가하였다. 특히 반응 온도 증가에 따라 BPSG의 식각 속도의 증가폭이 매우 높게 나타났다. HF/py에 알콜 공용매를 첨가하여 도 식각 부산물 감소에는 크게 효과가 없었다. HF/H2O의 식각률이 HF/py/alcohol 보다 높게 나타났지만 HF/H2O에 알콜 공용매를 첨가하였을 때는 오히려 식각률이 감소되었다. 캔틸레버 빔 구조를 초임계 이산화탄소 건식 식각으로 제조하여 높은 종횡비의 패턴구조물을 손상 없이 성공적으로 식각할 수 있었다.

The dry etching of sacrificial SiO2 was performed in supercritical carbon dioxide. The etching of boron phosphor silica glass (BPSG), tetraethyl orthosilicate (TEOS), thermal SiO2, and Si-nitride (SiN) was investigated by using a two chamber system with HF/py etchant and alcohol additives. The etch rate of sacrificial SiO2 increased upon the addition of methanol. The etch selectivity of BPSG with respect to SiN was highest with IPA although the highest etch rate was resulted from methanol except BPSG. The etch rate increased with the temperature in HF/py/MeOH system. Especially the increase of the etch rate was much higher for BPSG with an increase in the reaction temperature. The etch residue was not reduced apparently upon the addition of alcohol cosolvents to HF/py. While the etch rate in HF/H2O was higher than HF/py/alcohol system, the rate decreased with the addition of alcohols to HF/H2O. The cantilever beam structure of high aspect ratios was released by the dry ething in supercritical carbon dioxide without damage.

Keywords:Supercritical carbon dioxide;Dry etching;Sacrificial oxide;Cantilever beam;Stiction

[References]

De Moor P, Sedky S, VanHoof C, Proc. SPIE., 4028, 27 (2000)
Monk DJ, Soane DS, Howe RT, Transducer., 647 (1991)
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Saga K, Hattori T, Solid State Phenom., 134, 97 (2008)
Saga K, Kuniyasu H, Hattori T, Saito K, Mizobata I, Iwata T, Hirae S, Solid State Phenom., 134, 355 (2008)
Keagy JA, Zhang XG, Johnston KP, Busch E, Weber F, Wolf PJ, Rhoad T, J. Supercrit. Fluids, 39(2), 277 (2006)
Bessel CA, Denison GM, DeSimone JM, DeYoung J, Gross S, Schauer CK, Visintin PM, J. Am. Chem. Soc., 125(17), 4980 (2003)
Hoggan EN, Wang K, Flowers D, DeSimone JM, Carbonell RG, IEEE Trans. Semicond. Manuf., 17, 510 (2004)
Jones CA, Yang D, Irene EA, Gross SM, Wagner M, DeYoung J, DeSimone JM,, Chem. Mater., 15, 2867 (2003)
Malhouitre S, Hoeymissen JV, Case C, Granger P, ECS Transaction., 11, 71 (2007)
Li YX, Yang D, Jones CA, DeSimone JM, Irene EA, J. Vac. Sci. Technol. B, 25(4), 1139 (2007)
Jung JM, Ganapathy HS, Yuvaraj H, Johnston KP, Lim KT, Microelectron. Eng., 86, 165 (2009)
Jung JM, Yoon E, Lim E, Choi BC, Kim SY, Lim KT, Microelectron. Eng., 88, 3448 (2011)
Bae JH, Alam MZ, Jung JM, Gal YS, Lee H, Kim HG, Lim KT, Microelectron. Eng., 86, 128 (2009)

[Related Articles]

[1] De Moor P, Sedky S, VanHoof C, Proc. SPIE., 4028, 27 (2000)

[2] Monk DJ, Soane DS, Howe RT, Transducer., 647 (1991)

[3] Judge JS, J. Electrochem. Soc., 118, 1772 (1971)

[4] Monk DJ, Soane DS, J. Electrochem. Soc., 140, 2339 (1993)

[5] Jafri I, Busta H, Walsh S, Proc.-SPIE Int. Soc. Opt.Eng., 3880, 51 (1999)

[6] Watanabe H, Ohnishi S, Honma I, Kitajima H, Ono H, Wilhelm RJ, Sophie AJ, J. Electrochem. Soc., 142(1), 237 (1995)

[7] Saga K, Hattori T, Solid State Phenom., 134, 97 (2008)

[8] Saga K, Kuniyasu H, Hattori T, Saito K, Mizobata I, Iwata T, Hirae S, Solid State Phenom., 134, 355 (2008)

[9] Keagy JA, Zhang XG, Johnston KP, Busch E, Weber F, Wolf PJ, Rhoad T, J. Supercrit. Fluids, 39(2), 277 (2006)

[10] Bessel CA, Denison GM, DeSimone JM, DeYoung J, Gross S, Schauer CK, Visintin PM, J. Am. Chem. Soc., 125(17), 4980 (2003)

[11] Hoggan EN, Wang K, Flowers D, DeSimone JM, Carbonell RG, IEEE Trans. Semicond. Manuf., 17, 510 (2004)

[12] Jones CA, Yang D, Irene EA, Gross SM, Wagner M, DeYoung J, DeSimone JM,, Chem. Mater., 15, 2867 (2003)

[13] Malhouitre S, Hoeymissen JV, Case C, Granger P, ECS Transaction., 11, 71 (2007)

[14] Li YX, Yang D, Jones CA, DeSimone JM, Irene EA, J. Vac. Sci. Technol. B, 25(4), 1139 (2007)

[15] Jung JM, Ganapathy HS, Yuvaraj H, Johnston KP, Lim KT, Microelectron. Eng., 86, 165 (2009)

[16] Jung JM, Yoon E, Lim E, Choi BC, Kim SY, Lim KT, Microelectron. Eng., 88, 3448 (2011)

[17] Bae JH, Alam MZ, Jung JM, Gal YS, Lee H, Kim HG, Lim KT, Microelectron. Eng., 86, 128 (2009)