층간 절연막으로 응용하기 위한 저 유전체 불화탄소 플라즈마 고분자/SiO<sub>2</sub> 복합박막의 증착

김동선; 강나경; Dongsun Kim; Na-Kyung Kang

HWAHAK KONGHAK, Vol.39, No.1, 77-84, February, 2001

층간 절연막으로 응용하기 위한 저 유전체 불화탄소 플라즈마 고분자/SiO₂ 복합박막의 증착

Deposition of Low-Dielectric Fluorocarbon Plasma Polymer/SiO2 Composite Thin Film for Inter-layer Dielectric(ILD) Application

김동선 ^†, 강나경

공주대학교 공과대학 화학공학부, 충남 314-701

Dongsun Kim^†, and Na-Kyung Kang

School of Chemical Engineering, Kongju National University, 182 Shinkwandong, Kongju, Chungnam 314-701, Korea

E-mail:

초록

불화 탄소 박막 속에 소량의 SiO₂를 첨가함으로써 저 유전상수를 유지하면서 열 안정성이 뛰어난 불화탄소 플라즈마 고분자/SiO₂ 복합 박막을 개발하였다. 이들 박막들은 평판형 안테나를 가진 유도 결합형 플라즈마 화학 증착 반응기를 이용하여 불화탄소 원료 원으로 perfluorobenzene(C₆F₆)단량체, SiO₂ 원료 원으로 hexa-methyldisiloxane(HMDSO) 단량체를 사용하고, 수소와 산소를 사용한 일정 유량의 동반가스 하에서 HMDSO/(C₆F₆+HMDSO)의 비를 변화시키면서 증착하였다. FTIR 분석 결과에 의하면 증착된 복합 박막들은 "비정질 PTEE"(740 cm^-1 근방)와 "SiO₂"(1,070 cm^-1 근방)의 구조로 구성되어 있고, 유전 상수는 HMDSO/(C₆F₆+HMDSO)의 비의 변화에 따라 2.0에서 4.0 사이의 범위 내에서 변화하였다. 500℃ 온도까지 열처리하였을 때 박막의 두께 변화는 박막 속의 -OH 결합의 증발로 인해 -5% 범위 내에서 감소한 반면에 박막의 결합구조, 굴절률 계수, 그리고 유전 상수 등과 같은 박막의 특성은 거의 일정한 값을 유지하는 뛰어난 열 안정성을 보였다. 또한 박막의 두께에 대한 박막의 균질성을 보기 위해 거의 2㎛까지 약 2시간동안 증착하여 보았으나, 박막의 두께는 박막 증착 시간에 비례적으로 상승하였고 벗겨짐이 없이 안정하였으며 박막의 스트레스는 박막의 두께가 증가함에 따라 감소하였다.

The fluorocarbon plasma polymer/SiO2 composite films that exhibit excellent thermal stability(at least 450℃) and maintain low dielectric constant(between 2.0 to 4.0 depending on the ratio of source gases) were developed by incorporating a small amount of SiO2 into fluorocarbon thin films. The films were deposited by a planar-type inductively-coupled high density plasma chemical vapor deposition using perfluorobenzene(C6H6) as fluorocarbon source gas and hexamethyldisiloxane(HMDSO) as SiO2-film generating source gas. The infrared spectra of these composite films typically exhibited two distinctive absorption bands - one corresponding to SiO2(at around wavenumber 1,070 cm(-1)) and the other corresponding to amorphous PTFE(around wavenumber 740 cm(-1)). The dielectric constant was varied in the range of 2.0 to 4.0 with the ratio of the source gases. Also, these films exhibited good thermal stability - the variation of thickness is less than 5%, furthermore, the film maintained the dielectric constant and refractive index within 5% of its initial value when the film is subjected to temperature as high as 500℃. In order to investigate the change of film uniformity as film thickness is thicker, the films deposited up to 2 ㎛ for two hours were stable without peel-off and film stress was rather decreased with increasing film thickness.

Keywords:Low Dielectric Materials;Thin Films;High Density Plasma CVD;Inductively-Coupled Plasma

[References]

Bothra S, Rogers B, Kellam M, Osburn C, IEEE Trans. Electron Devices, 40, 591 (1994)
Murarka SP, Mater. Sci. Engineering, R19(3-4), 87 (1997)
Jeng SP, Chang MC, Kroger T, McAnally P, Havemann H, Digest of 1994 symp. On VLSI Technol., 73 (1994)
Applied Materials Inc., USA. Press Release, Centura HDP-CVD Provides Production-Ready Precision Gap Fill for 0.25 μm (1997)
Tasaka A, Komura A, Uchimoto Y, Inaba M, Ogumi Z, J. Polym. Sci. A: Polym. Chem., 34(2), 193 (1996)
Lang CI, Yang GR, Moore JA, Lu TM, Mater. Res. Soc. Symp. Proc., 381, 45 (1995)
Chiang C, Mack AS, Pan C, Ling YL, Fraser DB, Mat. Res. Soc. Symp. Proc., 381, 128 (1995)
Yota J, Joshi A, Nguyun C, Brongo M, Paladichuk S, 5th DUMIC Conference, 71 (1999)
Endo K, Matsubara Y, Kishimoto K, Iguchi M, Matsui T, 5th DUMIC Conference, 40 (1999)
Nguyen SV, IBM J. RES. DEVELOP., 43, 109 (1999)
Grill A, Patel V, Mater. Res. Soc. Symp. Proc., 443, 155 (1997)
Takeishi S, Kudo H, Shinohara R, Hoshino M, Fukuyama S, Yamaguchi J, Yamada M, J. Electrochem. Soc., 144(5), 1797 (1997)
Mountsier T, DUMIC Conference, 109 (1998)
Mountsier TW, Samuels JA, Thin Solid Films, 332(1-2), 362 (1998)
Xu P, Huang J, Singh K, Robles S, Yau WF, 5th DUMIC, 57 (1999)
Han LM, Timmon RB, Lee WW, J. Appl. Phys., 84, 439 (1998)
Hanyaloglu B, Aydinli A, Oye M, Aydi ES, Appl. Phys. Lett., 74, 606 (1999)
Yang H, Nguyen T, Ma Y, Hsu ST, 4th DUMIC Conference, 38 (1998)
Yun SM, Chang HY, Kang MS, Choi CK, Thin Solid Films, 341(1-2), 109 (1999)
Oh KS, Kang MS, Lee KM, Kim DS, Choi CK, Yun SM, Chang HY, Kim KH, Thin Solid Films, 345(1), 45 (1999)
Lau KKS, Labelle CB, Gleason KK, 5th DUMIC Conference, 11 (1999)
Labelle CB, Gleason KK, J. Vac. Sci. Technol., A17, 445 (1999)
Endo K, Tatsumi T, Matsubara Y, Horiuchi T, Jpn. J. Appl. Phys., 37, 1809 (1998)
Lieberman MA, Gottscho RA, "Design of High-Density Plasma Sources for Material Processing," Physics of Thin Films, Academic Press, Chapter 1 (1994)
Murarka SP, Solid State Technol., 83 (1996)
Naum C, Manolache S, Denes F, Langmuir, 16(2), 749 (2000)
Labelle CB, Gleason KK, J. Electrochem. Soc., 147(2), 678 (2000)
Wang X, Harris HR, Bouldin K, Temkin H, Gangopadhyay, J. Appl. Lett., 87, 621 (2000)
Back DM, "Fourier Transform Infrared Analysis of Thin Films," Physics of Thin Film, 18, chapter 1, Academic Press, New York (1991)
d'Agostino R, Cramarossa F, Fracassi F, "Plasma Deposition, Treatment, and Etching of Polymers," edited by R. d'Agostino, Chapter 2, Academic Press, New York (1990)

[Related Articles]

[1] Bothra S, Rogers B, Kellam M, Osburn C, IEEE Trans. Electron Devices, 40, 591 (1994)

[2] Murarka SP, Mater. Sci. Engineering, R19(3-4), 87 (1997)

[3] Jeng SP, Chang MC, Kroger T, McAnally P, Havemann H, Digest of 1994 symp. On VLSI Technol., 73 (1994)

[4] Applied Materials Inc., USA. Press Release, Centura HDP-CVD Provides Production-Ready Precision Gap Fill for 0.25 μm (1997)

[5] Tasaka A, Komura A, Uchimoto Y, Inaba M, Ogumi Z, J. Polym. Sci. A: Polym. Chem., 34(2), 193 (1996)

[6] Lang CI, Yang GR, Moore JA, Lu TM, Mater. Res. Soc. Symp. Proc., 381, 45 (1995)

[7] Chiang C, Mack AS, Pan C, Ling YL, Fraser DB, Mat. Res. Soc. Symp. Proc., 381, 128 (1995)

[8] Yota J, Joshi A, Nguyun C, Brongo M, Paladichuk S, 5th DUMIC Conference, 71 (1999)

[9] Endo K, Matsubara Y, Kishimoto K, Iguchi M, Matsui T, 5th DUMIC Conference, 40 (1999)

[10] Nguyen SV, IBM J. RES. DEVELOP., 43, 109 (1999)

[11] Grill A, Patel V, Mater. Res. Soc. Symp. Proc., 443, 155 (1997)

[12] Takeishi S, Kudo H, Shinohara R, Hoshino M, Fukuyama S, Yamaguchi J, Yamada M, J. Electrochem. Soc., 144(5), 1797 (1997)

[13] Mountsier T, DUMIC Conference, 109 (1998)

[14] Mountsier TW, Samuels JA, Thin Solid Films, 332(1-2), 362 (1998)

[15] Xu P, Huang J, Singh K, Robles S, Yau WF, 5th DUMIC, 57 (1999)

[16] Han LM, Timmon RB, Lee WW, J. Appl. Phys., 84, 439 (1998)

[17] Hanyaloglu B, Aydinli A, Oye M, Aydi ES, Appl. Phys. Lett., 74, 606 (1999)

[18] Yang H, Nguyen T, Ma Y, Hsu ST, 4th DUMIC Conference, 38 (1998)

[19] Yun SM, Chang HY, Kang MS, Choi CK, Thin Solid Films, 341(1-2), 109 (1999)

[20] Oh KS, Kang MS, Lee KM, Kim DS, Choi CK, Yun SM, Chang HY, Kim KH, Thin Solid Films, 345(1), 45 (1999)

[21] Lau KKS, Labelle CB, Gleason KK, 5th DUMIC Conference, 11 (1999)

[22] Labelle CB, Gleason KK, J. Vac. Sci. Technol., A17, 445 (1999)

[23] Endo K, Tatsumi T, Matsubara Y, Horiuchi T, Jpn. J. Appl. Phys., 37, 1809 (1998)

[24] Lieberman MA, Gottscho RA, "Design of High-Density Plasma Sources for Material Processing," Physics of Thin Films, Academic Press, Chapter 1 (1994)

[25] Murarka SP, Solid State Technol., 83 (1996)

[26] Naum C, Manolache S, Denes F, Langmuir, 16(2), 749 (2000)

[27] Labelle CB, Gleason KK, J. Electrochem. Soc., 147(2), 678 (2000)

[28] Wang X, Harris HR, Bouldin K, Temkin H, Gangopadhyay, J. Appl. Lett., 87, 621 (2000)

[29] Back DM, "Fourier Transform Infrared Analysis of Thin Films," Physics of Thin Film, 18, chapter 1, Academic Press, New York (1991)

[30] d'Agostino R, Cramarossa F, Fracassi F, "Plasma Deposition, Treatment, and Etching of Polymers," edited by R. d'Agostino, Chapter 2, Academic Press, New York (1990)