DOI QR코드

DOI QR Code

Effects of Wafer Cleaning and Heat Treatment in Glass/Silicon Wafer Direct Bonding

유리/실리콘 기판 직접 접합에서의 세정과 열처리 효과

  • Published : 2002.06.01

Abstract

We have investigated the effects of various wafers cleaning on glass/Si bonding using 4 inch Pyrex glass wafers and 4 inch silicon wafers. The various wafer cleaning methods were examined; SPM(sulfuric-peroxide mixture, $H_2SO_4:H_2O_2$ = 4 : 1, $120^{\circ}C$), RCA(company name, $NH_4OH:H_2O_2:H_2O$ = 1 : 1 : 5, $80^{\circ}C$), and combinations of those. The best room temperature bonding result was achieved when wafers were cleaned by SPM followed by RCA cleaning. The minimum increase in surface roughness measured by AFM(atomic force microscope) confirmed such results. During successive heat treatments, the bonding strength was improved with increased annealing temperatures up to $400^{\circ}C$, but debonding was observed at $450^{\circ}C$. The difference in thermal expansion coefficients between glass and Si wafer led debonding. When annealed at fixed temperatures(300 and $400^{\circ}C$), bonding strength was enhanced until 28 hours, but then decreased for further anneal. To find the cause of decrease in bonding strength in excessively long annealing time, the ion distribution at Si surface was investigated using SIMS(secondary ion mass spectrometry). tons such as sodium, which had been existed only in glass before annealing, were found at Si surface for long annealed samples. Decrease in bonding strength can be caused by the diffused sodium ions to pass the glass/si interface. Therefore, maximum bonding strength can be achieved when the cleaning procedure and the ion concentrations at interface are optimized in glass/Si wafer direct bonding.

References

  1. Appl. Phys. Lett. v.48 Wafer bonding for silicon on-insulator technologies J.B.Lasky https://doi.org/10.1063/1.96768
  2. J. Appl. Phys. v.60 Silicon-to-silicon direct bonding method M.Shimbo;K.Furukawa;K.Fukuda;K.Tanzawa https://doi.org/10.1063/1.337750
  3. Trans. KIEE v.46 A study on low-temperature bonding of glass-silicon using modified direct bonding method B.K.Ju;C.G.Ko;Y.H.Lee;I.B.Kang;P.White;N.Samaan;M.Haskard;M.H.Oh
  4. Proc. 1994 IEEE Intl. SOI Conference Formation of ultrathin single crystalline Si on glass by low temperature wafer direct bonding Q.Y.Tong;U.Goesele;T.Martini;M.Reiche
  5. Electronics Lett. v.31 Low temperature Pyrex glass wafer direct bonding F.Pigeon;B.Biasse;M.Zussy https://doi.org/10.1049/el:19950554
  6. Sensors and Actuators A : Physical v.72 Silicon-glass wafer bonding with silicon hydrophilic fusion bonding technology Z.X.Xiao;G.Y.Wu;Z.H.Li;G.B.Zhang;Y.L.Hao;Y.Y.Wang https://doi.org/10.1016/S0924-4247(98)00197-6
  7. 전기전자재료학회논문지 v.11 no.10 결정의존성 식각/기판 접합을 이용한 MEMS용 구조물의 제작 오명환;박정호;서상희;김철주;주병권;박흥우;박윤권;염상섭
  8. 전기전자재료학회논문지 v.12 no.7 APM 세정에 따른 표면 Microroughness 및 Si/SiO2 계의 전기적 특성에 관한 연구 정양희;김명규
  9. 전기전자재료학회 2001 하계학술대회논문집 큰 초기접합력을 갖는 Si 기관 직접접합에 관한 연구 김재민;정귀상;류지구;정연식
  10. ULSI Technology Wafer Cleaning Technology C.Y.Chang;T.S.Chao;C.Y.Chang(ed.);S.M.Sze(ed.)
  11. J. Electrochem. Soc. v.144 The crack opening method in silicon wafer bonding T.Martini;J.Steinkirchner;U.Goesele https://doi.org/10.1149/1.1837409
  12. Semiconductor Wafer Bonding : Science and Technology Q.Y.Tong;U.Goesele
  13. J.Phys.Chem.Ref.Data v.12 J.B.Pedley;E.M.Marshall https://doi.org/10.1063/1.555698