• Title/Summary/Keyword: Etch stop

Search Result 68, Processing Time 0.022 seconds

Electrochemical Etch-stop Characteristics of TMAH:IPA:Pyrazine Solutions (TMAH/IPA/Pyrazine용액에 있어서 전기화학적 식각정지 특성)

  • Chung, Gwiy-Sang;Lee, Chae-Bong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.04b
    • /
    • pp.147-151
    • /
    • 2000
  • This paper presents the electrochemical etch-stop characteristics of single-crystal silicon in a tetramethyl ammonium hyciroxide(TMAH):isopropyl alcohol(IPA):pyrazine solution. Addition of pyrazine to a TMAH:IPA etchant increases the etch-rate of (100) silicon, thus the elapsed time for etch-stop was shortened. The current-voltage(I-V) characteristics of n- and p-type silicon in a TMAH:IPA:pyrazine solution were obtained, respectively. Open circuit potential(OCP) and passivation potential(PP) of n- and p-type silicon, respectively, were obtained and applied potential was selected between n- and p-type silicon PP. The electrochemical etch-stop is applied to the fabrication of 801 microdiaphragms having $20\;{\mu}m$ thickness on a 5-inch silicon wafer. The averge thicknesses of 801 microdiaphragms fabricated on the one wafer were $20.03\;{\mu}m$ and standard deviation was ${\pm}0.26{\mu}m$. The silicon surface of the etch-stopped microdiaphragm was extremely flat without noticeable taper or other nonuniformities. The benefits of the electrochemical etch-stop in a TMAH:IPA:pyrazine solution become apparent when reproducibility in the microdiaphragm thickness for mass production is considered. These results indicate that the electrochemical etch-stop in a TMAH:IPA:pyrazine solution provides a powerful and versatile alternative process for fabricating high-yield silicon microdiaphragms.

  • PDF

Effects of Applied Bias Conditions on Electrochemical Etch-stop Characteristics (인가 바이어스 조건이 전기화학적 식각정지 특성에 미치는 영향)

  • 정귀상;강경두;김태송;이원재;송재성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.14 no.4
    • /
    • pp.263-268
    • /
    • 2001
  • This paper describes the effects of applied bias conditions on electrochemical etch-stop characteristics. THere are a number of key issues such as diode leakage and ohmic losses which arise when applying the conventional 3-electrochemical etch-stop to fabricated some of he MEMS(microelectro mechanical system) and SOI(Si-on-insulator) structures which employ SDB(Si-wafer direct bonding). This work allows to perform anin situ diagnostic to predict whether or not an electrochemical etch-stop would fail due to diode-leakage-induced premature passivation. In addition, it presents technology which takes into account the effects of ohmic losses and allows to calculate the appropriate bias necessary to obtain a successful electrochemical etch-stop.

  • PDF

Fabrication of Silicon Micromenbranes for MEMS Applications (MEMS용 실리콘 마이크로 멤브레인의 제작)

  • Chung, Gwiy-Sang;Park, Chin-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.05b
    • /
    • pp.7-12
    • /
    • 2000
  • This paper presents the electrochemical etch-stop characteristics of single-crystal silicon in a tetramethyl ammonium hydroxide(TMAH):isopropyl alcohol(IPA):pyrazine solution. Addition of pyrazine to a TMAH:IPA etchant increases the etch-rate of (100) silicon, thus the elapsed time for etch-stop was shortened. The current-voltage (I-V) characteristics of n- and p-type silicon in a TMAH:IPA:pyrazine solution were obtained, respectively. Open circuit potential(OCP) and passivation potential(PP) of n- and p-type silicon, respectively, were obtained and applied potential was selected between n- and p-type silicon PP. The electrochemical etch-stop is applied to the fabrication of 801 microdiaphragms having $20{\mu}m$ thickness on a 5-inch silicon wafer. The averge thicknesses of 801 microdiaphragms fabricated on the one wafer were $20.03{\mu}m$ and standard deviation was ${\pm}0.26{\mu}m$. The silicon surface of the etch-stopped microdiaphragm was extremely flat without noticeable taper or other nonuniformities. The benefits of the electrochemical etch-stop in a TMAH:IPA:pyrazine solution become apparent when reproducibility in the microdiaphragm thickness for mass production is considered. These results indicate that the electrochemical etch-stop in a TMAH:IPA:pyrazine solution provides a powerful and versatile alternative process for fabricating high-yield silicon microdiaphragms.

  • PDF

Electrochemical Etch-Stop Suitable for MEMS Applications

  • Chung, Gwiy-Sang;Kim, Sun-Chunl;Kim, Tae-Song
    • Transactions on Electrical and Electronic Materials
    • /
    • v.2 no.2
    • /
    • pp.26-31
    • /
    • 2001
  • This paper presents the electrochemical etch-stop characteristics of single-crystal Si(001) wafers in tetramethyl ammonium hydroxide(TMAH):isopropyl alcohol(IPA):pyrazine solutions. The addition of pyrazine to TMAH:IPA solutions increased the etch rate of (100) Si, thus the etching time required by the etch-stop process shortened. The current-voltage(I-V) characteristics of n- and p-type Si in TMAH:IPA:pyrazine solutions were obtained, respectively. Open circuit potential(OCP) and passivation potential(PP) of n- and p-type Si, respectively, were obtained and applied potential was selected between n- and p-type Si PPs. The electrochemical etch-stop method was used to fabricate 801 microdiaphragms of 20 ${\mu}{\textrm}{m}$ thickness on a 5-inch Si wafer. The average thickness of fabricated 801 microdiaphragms on one Si wafer was 20.03 ${\mu}{\textrm}{m}$ and the standard deviation was $\pm$0.26 ${\mu}{\textrm}{m}$. The Si surface of the etch-stopped microdiaphragm was extremely flat with no noticeable taper or nonuniformity.

  • PDF

Employing Al Etch Stop Layer for Nb-based SNS Josephson Junction Fabrication Process (Al 식각정지층을 이용한 Nb-based SNS 조셉슨 접합의 제조공정)

  • Choi, J.S.;Park, J.H.;Song, W.;Chong, Y.
    • Progress in Superconductivity
    • /
    • v.12 no.2
    • /
    • pp.114-117
    • /
    • 2011
  • We report our efforts on the development of Nb-based non-hysteretic Josephson junction fabrication process for quantu device applications. By adopting and modifying the existing Nb-aluminum oxide tunnel junction process, we develop a process for non-hysteretic Josephson junction circuits using metal-silicide as metallic barrier material. We use sputter deposition of Nb and $MoSi_2$, PECVD deposition of silicon oxide as insulator material, and ICP-RIE for metal and oxide etch. The advantage of the metal-silicide barrier in the Nb junction process is that it can be etched in $SF_6$ RIE together with Nb electrode. In order to define a junction area precisely and uniformly, end-point detection for the RIE process is critical. In this paper, we employed thin Al layer for the etch stop, and optimized the etch condition. We have successfully demonstrated that the etch stop properties of the inserted Al layer give a uniform etch profile and a precise thickness control of the base electrode in Nb trilayer junctions.

Fabrication of 3-Dimensional Microstructures for Bulk Micromachining by SDB and Electrochemical Etch-Stop (SDB와 전기화학적 식각정지에 의한 벌크 마이크로머신용 3차원 미세구조물 제작)

  • 정귀상;김재민;윤석진
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.15 no.11
    • /
    • pp.958-962
    • /
    • 2002
  • This paper reports on the fabrication of free-standing microstructures by DRIE (deep reactive ion etching). SOI (Si-on-insulator) structures with buried cavities are fabricated by SDB (Si-wafer direct bonding) technology and electrochemical etch-stop. The cavity was formed the upper handling wafer by Si anisotropic etch technique. SDB process was performed to seal the formed cavity under vacuum condition at -760 mmHg. In the SDB process, captured air and moisture inside of the cavities were removed by making channels towards outside. After annealing (100$0^{\circ}C$, 60 min.), the SDB SOI structure with a accurate thickness and a good roughness was thinned by electrochemical etch-stop in TMAH solution. Finally, it was fabricated free-standing microstructures by DRIE. This result indicates that the fabrication technology of free-standing microstructures by combination SDB, electrochemical etch-stop and DRIE provides a powerful and versatile alternative process for high-performance bulk micromachining in MEMS fields.

Fabrication of High-yield Si Thin-membranes by Electrochemical Etch-stop (전기화학적 식각정지에 의한 고수율 실리콘 박막 멤브레인 제작)

  • 정귀상;박진상;이원재;송재성
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.14 no.3
    • /
    • pp.223-227
    • /
    • 2001
  • In this paper, the authors present the fabrication of high-yield Si thin-membranes by electrochemical etch-stop in tetramethyl ammonium hydroxide (TMAH): isopropyl alcohol (IPA):pyrazine solutions. The current-voltage (I-V) characteristics of n- and p-type Si in TMAH:IPA;pyrazine solutions were analysed, repsectively. Open circuit potential (OCP)and passivation potential (PP) of n- and p-type Si, respectively, were obtained and applied potential was selected between n- and p-type Si PPs. The electrochemical etch-stop method was applied to the fabrication of 801 micro-membranes with 20.0 $\mu\textrm{m}$ thickness on a 5" Si wafer. The average thickness of fabricated 801 micro-membranes on one wafer 20.03$\mu\textrm{m}$ and the standard deviation was ${\pm}$0.26$\mu\textrm{m}$. The Si surface of the etch-stopped micro-membranes was extremely flat with no noticeable taper or nonuniformity. The results indicate that use of the electrochemical etch-stop method for the etching of Si in TMAH:IPA;pyrazine solutions provides a powerful and versatile alternative process for fabricating high-yield Si micro-membranes.

  • PDF

A study on SOI structures thinning by electrochemical etch-stop (전기화학적 식각정지에 의한 SOI 박막화에 관한 연구)

  • 강경두;정수태;류지구;정재훈;정귀상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.11a
    • /
    • pp.583-586
    • /
    • 2000
  • The non-selective method by polishing after grinding was used widely to thinning of SDB SOI structures. This method was very difficult to thickness control of thin film, and it was dependent on equipments. However electrochemical etch-stop, one of the selective methods, was able to accurately thickness control and etch equipment was very simple. Therefore, this paper described with the effect of leakage current and electrodes on electrochemical etch-stop. Consequentially, PP(passivation potential) was changed according to the kinds of contact and contact sizes, but OCP(open current potential) was not change with range of -1.5~-1.3V

  • PDF

Fabrication of SOI structures whit buried cavities by SDB and elelctrochemical etch-stop (SDB와 전기화학적 식각정지에 의한 매몰 cavity를 갖는 SOI구조의 제작)

  • 강경두;정수태;류지구;정재훈;김길중;정귀상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.11a
    • /
    • pp.579-582
    • /
    • 2000
  • This paper described on the fabrication of SOI(Si-on-insulator) structures with buried cavities by SDB technology and eletrochemical etch-stop. The cavity was fabricated the upper handling wafer by Si anisotropic etch technique. SDB process was performed to seal the fabricated cavity under vacuum condition at -760mmHg. In the SDB process, captured air and moisture inside of the cavities were removed by making channels towards outside. After annaling(100$0^{\circ}C$, 60 min.), the SDB SOI structure was thinned by electrochemical etch-stop. Finally, it was fabricated the SDB SOI structure with buried cavities as well as an accurate control and a good flatness.

  • PDF

Flatness of a SOB SOI Substrate Fabricated by Electrochemical Etch-stop (전기화학적 식각정지에 의해 제조된 SDB SOI기판의 평탄도)

  • Chung, Gwiy-Sang;Kang, Kyung-Doo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.04b
    • /
    • pp.126-129
    • /
    • 2000
  • This paper describes on the fabrication of a SOI substrate by SDB technology and electrochemical etch-stop. The surface of the thinned SDB SOI substrate is more uniform than that of grinding or polishing by mechanical method, and this process was found to be very accurate method for SOI thickness control. During electrochemical etch-stop, leakage current versus voltage curves were measured for analysis of the open current potential (OCP) point, the passivation potential (PP) point and anodic passivation potential. The surface roughness and the controlled thickness selectivity of the fabricated a SDB SOI substrate were evaluated by using AFM and SEM, respectively.

  • PDF