• 한국전기전자재료학회논문지
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• 제15권6호
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• pp.479-485
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• 2002

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.

• 한국재료학회지
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• 제14권11호
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• pp.780-785
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• 2004

The degradation mechanism of soft magnetic properties of $Fe-Hf-N/Cr/SiO_2$ thin films reacted with a bonding glass was investigated. When $Fe-Hf-N/Cr/SiO_2$ films were annealed under $600^{\circ}C$ without the bonding glass, the compositions and the soft magnetic properties of Fe-Hf-N layers were not changed. However, after reaction with the bonding glass at $550^{\circ}C$, the soft magnetic properties of the film were degraded. At $600^{\circ}C$, the saturation magnetization of the reacted film decreased to 13.5 kG, and its coercivity increased to 4 Oe, and its effective permeability decreased to 700. It was founded that O diffused from the glass into the Fe-Hf-N layers during the reaction and generated $HfO_2$ phases. It was considered that the soft magnetic properties of the $Fe-Hf-N/Cr/SiO_2$ films reacted with the bonding glass were primarily degraded by the formation of the Fe-Hf-O-N layer of which the Fe content was below 60 $at\%$, and secondarily degraded by the Fe-Hf-O-N layer above 70 $at\%$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1943-1945
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• 1996

In this paper, we developed a modified direct bonding method for the application of vacuum devices. By the proposed method, we successfully bonded the following materials: Si-Si, Si-$SiO_2$-Si, glass-Si, and glass-$SiO_2$-Si. In our experiments, we used corning #7070 wafer type glass and (100) or (110) single crystalline silicon wafers. In order to enhance the initial bonding strength we contacted the materials to be bonded as D. I. water wetted on the surfaces and evaporated the water under the room temperature and atmosphere environment. Finally we realized the glass bonding by simple direct bonding method which has been performed by electrostatic bonding method until now.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.374-375
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• 2006

This paper describes anodic bonding characteristics of MCA to Si-wafer using evaporated Pyrex #7740 glass thin-films for MEMS applications. Pyrex #7740 glass thin-films with the same properties were deposited on MCA under optimum RF sputter conditions (Ar 100 %, input power $1\;W/cm^2$). After annealing at $450^{\circ}C$ for 1 hr, the anodic bonding of MCA to Si-wafer was successfully performed at 600 V, $400^{\circ}C$ in $110^{-6}$ Torr vacuum condition. Then, the MCA/Si bonded interface and fabricated Si diaphragm deflection characteristics were analyzed through the actuation and simulation test. It is possible to control with accurate deflection of Si diaphragm according to its geometries and its maximum non-linearity being 0.05-0.08 %FS. Moreover, any damages or separation of MCNSi bonded interfaces did not occur during actuation test. Therefore, it is expected that anodic bonding technology of MCNSi-wafers could be usefully applied for the fabrication process of high-performance piezoelectric MEMS devices.

• 마이크로전자및패키징학회지
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• 제16권1호
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• pp.27-31
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• 2009

본 논문에서는 웨이퍼 레벨 기술을 이용한 CIS용 폴리머 접합 기술을 연구하고 접합 후의 warpage 분석과 개별 패키지의 신뢰성 테스트를 수행하였다. 균일한 접합 높이를 유지하기 위하여 glass 웨이퍼 상에 dam을 형성하고 접합용 폴리머 층을 patterning하여 Si과 glass 웨이퍼의 접합 테스트를 수행하였다. Si 웨이퍼의 접합온도, 접합 압력 그리고 접합 층이 낮을수록 warpage 결과가 감소하였으며 접합시간과 승온 시간이 짧을수록 warpage 결과가 증가하는 것을 확인하였다. 접합 된 웨이퍼를 dicing 하여 각 개별 칩 단위로 TC, HTC, Humidity soak의 신뢰성 테스트를 수행하였으며 warpage 결과가 패키지의 신뢰성 결과에 미치는 영향은 미비한 것으로 확인되었다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1999년도 특별강연 및 추계학술발표대회 개요집
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• pp.247-250
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• 1999

• 한국자기학회지
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• 제13권1호
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• pp.6-14
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• 2003

열처리 온도에 따라 접합유리와의 화학적 반응이 Fe-Hf-N/SiO$_2$, 및 Fe-Hf-N/Cr/SiO$_2$ 박막의 물리적, 자기적 특성에 미치는 영향을 고찰하였다. 접합유리와 반응된 Fe-Hf-N/SiO$_2$ 박막의 연자기 특설은 온도가 증가함에 따라 크게 떨어졌으며, $600^{\circ}C$에서 포화자화값은 1 kG, 보자력이 27 Oe, 10MHz에서의 유효투자율이 70로 자기적 특성이 급격히 열화되었다. 이는 접합유리와의 화학적 반응에 의해 Fe-Hf-N 박막이 H$_{f}$ O$_2$, Fe$_3$O$_4$ 등으로 산화되기 때문인 것으로 나타났다. Fe-Hf-N/Cr/SiO$_2$ 박막의 경우, $600^{\circ}C$에서 포화자화값 13.5kG, 보자력은 4Oe, 10 MHz에서의 유효 투자율이 700으로 Fe-Hf-N/SiO$_2$ 박막보다 연자기 특성 열화가 덜 일어났다. 이는 Fe-Hf-N/Cr/SiO$_2$ 박막의 Cr 층이 Fe-Hf-N 박막의 산화를 억제하여. 일부에서만 HfO$_2$가 생성되고 나머지는 원래의 $\alpha$-Fe상을 유지하기 때문인 것으로 나타났다.

• 센서학회지
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• 제29권5호
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• pp.354-359
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• 2020

The high vacuum hermetic sealing technique ensures excellent performance of MEMS resonators. For the high vacuum hermetic sealing, the customization of anodic bonding equipment was conducted for the glass/Si/glass triple-stack anodic bonding process. Figure 1 presents the schematic of the MEMS resonator with triple-stack high-vacuum anodic bonding. The anodic bonding process for vacuum sealing was performed with the chamber pressure lower than 5 × 10^-6 mbar, the piston pressure of 5 kN, and the applied voltage was 1 kV. The process temperature during anodic bonding was 400 ℃. To maintain the vacuum condition of the glass cavity, a getter material, such as a titanium thin film, was deposited. The getter materials was active at the 400 ℃ during the anodic bonding process. To read out the electrical signals from the Si resonator, a vertical feed-through was applied by using through glass via (TGV) which is formed by sandblasting technique of cap glass wafer. The aluminum electrodes was conformally deposited on the via-hole structure of cap glass. The TGV process provides reliable electrical interconnection between Si resonator and aluminum electrodes on the cap glass without leakage or electrical disconnection through the TGV. The fabricated MEMS resonator with proposed vacuum packaging using three-layer anodic bonding process has resonance frequency and quality factor of about 16 kHz and more than 40,000, respectively.

• 센서학회지
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• 제12권6호
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• pp.265-272
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• 2003

본 논문은 파이렉스 #7740 유리 박막을 이용한 MEMS용 MLCA (Multi Layer Ceramic Actuator)와 Si기판의 양극접합 특성에 관한 것이다. 최적의 RF 마그네트론 스피터링 조건 (Ar 100%, input power $1\;W/cm^2$)하에서 MLCA기판위에 파이렉스 #7740 유리의 특성을 갖는 박막을 증착하였다. $450^{\circ}C$에서 1시간 열처리한 다음, -760 mmHg, 600V 그리고 $400^{\circ}C$에서 1시간동안 양극접합했다. 그 다음에 Si 다이어프램을 제조한 후, MLCA/Si 접합계면과 MLCA 구동을 통한 Si 다이어프램 변위특성을 분석 및 평가하였다. 다이어프램 형상에 따라 정밀한 변위 세어가 가능했으며 0.05-0.08 %FS의 우수한 선형성을 나타내었다. 또한, 측정동안 접합계면 균열이나 계면분리가 일어나지 않았다. 따라서, MLCA/Si기판 양각접합기술은 고성능 압전 MEMS 소자 제작공정에 유용하게 사용가능할 것이다.

• 한국세라믹학회지
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• 제20권1호
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• pp.70-78
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• 1983

This paper discusses the application of Si-Borosilicate glass sealing to a new sealing method which utilizes a large electrostatic field to pormote bound formation at relatively low temperature. Bonding mechanism and the effect of bonding time bonding temperature glass thickness and surface roughness on the bond strength were investigated. Application of a de voltage across bonded specimen gradually produced a layer of glass adjacent silicon which was depleted of mobile ions. As a consequence a n increasingly larger fraction of the applied voltage appeared across the depleted region and very large electric field resulted This field accompanyed by large electrostatic force acted as driving force the of strong bond. And stronger bond was formed with increasing bonding time and temperature. A low temperature preoxidation is advantageous for the Si surface having a rougher surface finish that 1 microinch.