• 한국전기전자재료학회논문지
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• 제15권10호
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• pp.883-888
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• 2002

SiC direct bonding technology is very attractive for both SiCOI(SiC-on-insulator) electric devices and SiC-MEMS(micro electro mechanical system) fields because of its application possibility in harsh environments. This paper presents pre-bonding techniques with variation of HF pre-treatment conditions for SiC wafer direct bonding using PECVD(plasma enhanced chemical vapor deposition) oxide. The PECYD oxide was characterized by XPS(X-ray photoelectron spectrometer) and AFM(atomic force microscopy). The characteristics of the bonded sample were measured under different bonding conditions of HF concentration and an applied pressure. The bonding strength was evaluated by the tensile strength method. The bonded interface was analyzed by using SEM(scanning electron microscope). Components existed in the interlayer were analyzed by using FT-IR(fourier transform infrared spectroscopy). The bonding strength was varied with HF pre-treatment conditions before the pre-bonding in the range of 5.3 kgf/cm$^2$to 15.5 kgf/cm$^2$.

• 한국재료학회지
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• 제8권10호
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• pp.890-897
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• 1998

n-InP(001)기판과 PECVD법으로 ${Si}_3N_4$(200nm)막이 성장된 InP 기판사이의 direct wafer bonding을 분석하였다. 두 기판을 접촉시켰을 때 이들 사이의 결합력에 크게 영향을 주는 표면 상태를 접촉각 측정과 AFM을 통해서 분석하였다. InP 기판은 $50{\%}$ 불산용액으로 에칭하였을 때 접촉각이 $5^{\circ}$, RMS roughness는 $1.54{\AA}$이었다. ${Si}_3N_4$는 암모니아수 용액으로 에칭하였을 때 RMS roughness가 $3.11{\AA}$이었다. Inp 기판과 ${Si}_3N_4$/InP를 각각 $50{\%}$ 불산 용액과 암모니아수 용액에 에칭한 후 접촉시켰을 때 상당한 크기의 초기 겹합력을 관찰할 수 있었다. 기계적으로 결합된 시편을 $580^{\circ}C$-$680^{\circ}C$, 1시간동안 수소 분위기와 질소분우기에서 열처리하였다. SAT(Scanning Acoustic Tomography)측정으로 두 기판 사이의 결합여부를 확인하였다. shear force로 측정한 InP 기판과 ${Si}_3N_4$/InP사이의 결합력은 ${Si}_3N_4$/InP 계면의 결합력만큼 증가되었다. TEM과 AES를 이용해서 di-rect water bonding 계면과 PECVD계면을 분석하였다.

• 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.

• 한국전기전자재료학회논문지
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• 제16권8호
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• pp.700-704
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• 2003

This paper describes on characteristics of 2" 3C-SiC wafer bonding using PECVD (plasma enhanced chemical vapor deposition) oxide and HF (hydrofluoride acid) for SiCOI (SiC-on-Insulator) structures and MEMS (micro-electro-mechanical system) applications. In this work, insulator layers were formed on a heteroepitaxial 3C-SiC film grown on a Si (001) wafer by thermal wet oxidation and PECVD process, successively. The pre-bonding of two polished PECVD oxide layers made the surface activation in HF and bonded under applied pressure. The bonding characteristics were evaluated by the effect of HF concentration used in the surface treatment on the roughness of the oxide and pre-bonding strength. Hydrophilic character of the oxidized 3C-SiC film surface was investigated by ATR-FTIR (attenuated total reflection Fourier transformed infrared spectroscopy). The root-mean-square suface roughness of the oxidized SiC layers was measured by AFM (atomic force microscope). The strength of the bond was measured by tensile strength meter. The bonded interface was also analyzed by IR camera and SEM (scanning electron microscope), and there are no bubbles or cavities in the bonding interface. The bonding strength initially increases with increasing HF concentration and reaches the maximum value at 2.0 ％ and then decreases. These results indicate that the 3C-SiC wafer direct bonding technique will offers significant advantages in the harsh MEMS applications.ions.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.3313-3315
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• 1999

Si direct bonding(SDB) technology is very attractive for both Si-on-insulator(SOI) electric devices and MEMS applications because of its stress free structure and stability. This paper presents on pre-bonding according to HF pre-treatment conditions in Si wafer direct bonding. The characteristics of bonded sample were measured under different bonding conditions of HF concentration, and applied pressure. The bonding strength was evaluated by tensile strength method. The bonded interface and the void were analyzed by using SEM and IR camera respectively. A bond characteristic on the interface was analyzed by using IT- IR. Si-F bonds on Si surface after HF pre-treatment are replaced by Si-OH during a DI water rinse. Consequently, hydrophobic wafer was bonded by hydrogen bonding of Si $OH{\cdots}(HOH{\cdots}HOH{\cdots}HOH){\cdots}OH-Si$. The bond strength depends on the HF pre-treatment condition before pre- bonding (Min:$2.4kgf/crn^2{\sim}Max:14.9kgf/crn^2$)

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.86-87
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• 2015

An active study on UHPC, which has been recently used in high-rise building and bridges, is in progress. However, research on bonding shear strength of UHPC is required to be studied due to the lack of information. In this study, experimental research progress for bonding shear strength (shear strength of adhesive surface) evaluation of UHPC (Ultra High Performance Concrete) is proceeded. First, specimens that surface treatment methods of concrete bonded section and retardation time of placement are considered are produced. Second, Direct Shear test is applied on concrete bonded section of UHPC. As a result of this study, the highest bonding shear strength specimen in which compared to the non-retardation time specimen is compaction turbulence treatment. From later study, it is judged that strength of UHPC in accordance with direction of steel fiber when steel fiber of UHPC is mixed.

• 대한치과교정학회지
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• 제48권4호
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• pp.245-252
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• 2018

Objective: We aimed to perform in-vitro evaluation to compare 1) shear bond strength (SBS), adhesive remnant index (ARI), and color change between self-etched and acid-etched primers; 2) the SBS, ARI and color change between direct and indirect bonding; and 3) the enamel roughness (ER) between 12-blade bur and aluminum oxide polisher debonding methods. Methods: Seventy bovine incisors were distributed in seven groups: control (no bonding), direct (DTBX), and 5 indirect bonding (ITBX, IZ350, ISONDHI, ISEP, and ITBXp). Transbond XT Primer was used in the DTBX, ITBX, and ITBXp groups, flow resin Z350 in the IZ350 group, Sondhi in the ISONDHI group, and SEP primer in the ISEP group. SBS, ARI, and ER were evaluated. The adhesive remnant was removed using a low-speed tungsten bur in all groups except the ITBXp, in which an aluminum oxide polisher was used. After coffee staining, color evaluations were performed using a spectrophotometer immediately after staining and prior to bonding. Results: ISONDHI and ISEP showed significantly lower SBS (p < 0.01). DTBX had a greater number of teeth with all the adhesive on the enamel (70%), compared with the indirect bonding groups (0-30%). The ER in the ITBX and ITBXp groups was found to be greater because of both clean-up techniques used. Conclusions: Direct and indirect bonding have similar results and all the primers used show satisfactory adhesion strength. Use of burs and polishers increases the ER, but polishers ensure greater integrity of the initial roughness. Resin tags do not change the color of the teeth.

• 접착 및 계면
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• 제1권1호
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• pp.30-37
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• 2000

고무-섬유로 이루어진 고무복합체 제조공정을 단순화하기 위한 직접블렌딩 기술을 본 연구에서 제시하였다. 직접블렌딩 방법은 레소시놀, 헥사메틸테트라민, NaOH로 이루어진 결합체를 고무혼합물 배합공정에 직접 혼합하여 보강섬율의 접착제 처리공정을 생략할 수 있는 방법이다. 이러한 직접블렌딩 메커니즘을 규명하기 위해 결합체를 직접 고무혼합물에 블렌딩한 경우와(Case I) 결합체를 수용액 상에서 반응시켜 경화물을 얻은 후 이를 분쇄하여 고무혼합물에 배합하는 경우를(Case II) 비교하였다. 모폴로지 분석결과에 의하면 Case II의 경우 결합체와 매트릭스 고무 사이에 뚜렷한 계면이 발생하였지만, Case I의 경우 적절한 가공조건 아래서 결합제와 매트릭스 고무 사이의 반응에 의해 새로운 상이 생성됨을 알 수 있었다. 또한, SBR-나일론 고무복합체의 최적 성능을 위한 결합제의 최적 조성은 레소시놀과 헥사메틸렌테트라민의 mole비가 1.2:1인, 즉 레소시놀과 포름알데히드의 mole비가 1:5인 조성이었다.

• 마이크로전자및패키징학회지
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• 제22권3호
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• pp.31-38
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• 2015

본 연구에서는 실리콘 웨이퍼의 고속 직접접합 공정을 위하여 상압 플라즈마와 함께 에어로젤 형태의 초순수 분사를 이용하여 표면처리 활성화 및 결함이 없는 실리콘 직접접합 공정을 개발하였다. 플라즈마 공정의 다양한 인자, 즉 $N_2$ 가스의 유량, CDA(clean dry air)의 유량, 플라즈마 헤드와 기판 간의 간격, 플라즈마의 인가전압이 플라즈마 활성화, 즉 친수화 처리에 미치는 영향을 접촉각 측정을 통하여 관찰하였다. 또한 열처리 온도 및 열처리 시간이 접합 강도에 미치는 영향을 연구하였으며, 접합 강도의 측정은 crack opening 방법을 이용하였다. 접합 강도가 제일 높은 최적의 열처리 조건은 $400^{\circ}C$의 열처리 온도 및 2 시간의 열처리 시간이었다. 플라즈마 스캔 속도 및 스캔 횟수를 실험계획법을 이용하여 최적화한 결과, 스캔 속도는 30 mm/sec, 스캔 횟수는 4 회에서 최적의 접합 강도를 나타내고 있었다. 열처리 조건과 플라즈마 활성화 조건을 최적화 한 후 직접접합을 하여 적외선투과현미경 등을 이용하여 관찰한 결과, 접합된 웨이퍼에서 접합 공정으로 인한 공극이나 결함은 관찰되지 않았다. 접합된 웨이퍼의 접합 강도는 평균 $2.3J/m^2$의 접합 강도를 나타내고 있었다.

• 한국전기전자재료학회논문지
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• 제15권4호
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• pp.301-307
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• 2002

Direct bonded SOI wafer pairs with $Si ll SiO_2/Si_3N_4 ll Si$ the heterogeneous insulating layers of SiO$_2$-Si$_3$N$_4$are able to apply to the micropumps and MEMS applications. Direct bonding should be executed at low temperature to avoid the warpage of the wafer pairs and inter-diffusion of materials at the interface. 10 cm diameter 2000 ${\AA}-SiO_2/Si(100}$ and 560 $\AA$- ${\AA}-Si_3N_4/Si(100}$ wafers were prepared, and wet cleaned to activate the surface as hydrophilic and hydrophobic states, respectively. Cleaned wafers were pre- mated with facing the mirror planes by a specially designed aligner in class-100 clean room immediately. We employed a heat treatment equipment so called fast linear annealing(FLA) with a halogen lamp to enhance the bonding of pre mated wafers We kept the scan velocity of 0.08 mm/sec, which implied bonding process time of 125 sec/wafer pairs, by varying the heat input at the range of 320~550 W. We measured the bonding area by using the infrared camera and the bonding strength by the razor blade clack opening method, respective1y. It was confirmed that the bonding area was between 80% and to 95% as FLA heat input increased. The bonding strength became the equal of $1000^{\circ}C$ heat treated $Si ll SiO_2/Si_3N_4 ll Si$ pair by an electric furnace. Bonding strength increased to 2500 mJ/$\textrm{m}^2$as heat input increased, which is identical value of annealing at $1000^{\circ}C$-2 hr with an electric furnace. Our results implies that we obtained the enough bonding strength using the FLA, in less process time of 125 seconds and at lowed annealing temperature of $400^{\circ}C$, comparing with the conventional electric furnace annealing.