Seed Polarity Dependence of SiC SingleCrystal Growth by Using a Physical Vapor Transport Method

Jung-Gon Kim,Chang-Hyun Son,Jung-Woo Choi,Jung-Kyu Kim,Byoung-Chul Shin,Il-Soo Kim,S. Nishino,이원재,서정두,구갑렬 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.54 No.5

6H-SiC single crystal ingots grown by using the sublimation physical vapor transport (PVT) technique were prepared on two-seed crystals with opposite face polarities; then, SiC crystal wafers sliced from the SiC ingot were systematically investigated to find out the polarity dependence of the crystal quality. The growth rate of the 2-inch SiC crystal grown in this study was about 0.3 mm/hr. n-type 200 SiC single crystals exhibiting the polytype of 6H-SiC were successfully fabricated. The incorporation of nitrogen donors in the SiC crystals grown on the C-face seed crystal was shown to be higher than in SiC crystals grown on a Si-face crystal. When the SiC crystal ingot proceeded to grow, the SiC crystal region grown on the C-face seed crystal was enlarged compared to the SiC crystal region on the Si-face seed crystal; finally a SiC crystal having only a C-face was obtained. X- ray rocking curves and reciprocal space mappings (RSM) definitely revealed a better crystal quality for the SiC crystal grown on the C-face seed crystal than for the SiC crystal grown on the Si-face. 6H-SiC single crystal ingots grown by using the sublimation physical vapor transport (PVT) technique were prepared on two-seed crystals with opposite face polarities; then, SiC crystal wafers sliced from the SiC ingot were systematically investigated to find out the polarity dependence of the crystal quality. The growth rate of the 2-inch SiC crystal grown in this study was about 0.3 mm/hr. n-type 200 SiC single crystals exhibiting the polytype of 6H-SiC were successfully fabricated. The incorporation of nitrogen donors in the SiC crystals grown on the C-face seed crystal was shown to be higher than in SiC crystals grown on a Si-face crystal. When the SiC crystal ingot proceeded to grow, the SiC crystal region grown on the C-face seed crystal was enlarged compared to the SiC crystal region on the Si-face seed crystal; finally a SiC crystal having only a C-face was obtained. X- ray rocking curves and reciprocal space mappings (RSM) definitely revealed a better crystal quality for the SiC crystal grown on the C-face seed crystal than for the SiC crystal grown on the Si-face.

Low temperature deposition of polycrystalline silicon thin films on a flexible polymer substrate by hot wire chemical vapor deposition

Lee, Sang-hoon,Jung, Jae-soo,Lee, Sung-soo,Lee, Sung-bo,Hwang, Nong-moon Elsevier 2016 Journal of crystal growth Vol.453 No.-

<P><B>Abstract</B></P> <P>For the applications such as flexible displays and solar cells, the direct deposition of crystalline silicon films on a flexible polymer substrate has been a great issue. Here, we investigated the direct deposition of polycrystalline silicon films on a polyimide film at the substrate temperature of 200°C. The low temperature deposition of crystalline silicon on a flexible substrate has been successfully made based on two ideas. One is that the Si–Cl–H system has a retrograde solubility of silicon in the gas phase near the substrate temperature. The other is the new concept of non-classical crystallization, where films grow by the building block of nanoparticles formed in the gas phase during hot-wire chemical vapor deposition (HWCVD). The total amount of precipitation of silicon nanoparticles decreased with increasing HCl concentration. By adding HCl, the amount and the size of silicon nanoparticles were reduced remarkably, which is related with the low temperature deposition of silicon films of highly crystalline fraction with a very thin amorphous incubation layer. The dark conductivity of the intrinsic film prepared at the flow rate ratio of <I>R</I> <SUB>HCl</SUB>=[HCl]/[SiH<SUB>4</SUB>]=3.61 was 1.84×10<SUP>–6</SUP> Scm<SUP>−1</SUP> at room temperature. The Hall mobility of the n-type silicon film prepared at <I>R</I> <SUB>HCl</SUB>=3.61 was 5.72cm<SUP>2</SUP> V<SUP>−1</SUP>s<SUP>−1</SUP>. These electrical properties of silicon films are high enough and could be used in flexible electric devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Polycrystalline silicon thin films was successfully deposited on a polyimide film. </LI> <LI> The crystalline silicon films were deposited based non-classical crystallization. </LI> <LI> By adding HCl, the amount and the size of silicon nanoparticles were reduced. </LI> </UL> </P>

단결정 실리콘 잉곳 결정성장 속도에 따른 고-액 경계면 형성 및 Defect 최적화

전혜준(Hye Jun Jeon),박주홍(Ju Hong Park),블라디미르 아르테미예프(Vladimir Artemyev),정재학(Jae Hak Jung) 한국태양광발전학회 2020 Current Photovoltaic Research Vol.8 No.1

It is clear that monocrystalline Silicon (Si) ingots are the key raw material for semiconductors devices. In the present industries markets, most of monocrystalline Silicon (Si) ingots are made by Czochralski Process due to their advantages with low production cost and the big crystal diameters in comparison with other manufacturing process such as Float-Zone technique. However, the disadvantage of Czochralski Process is the presence of impurities such as oxygen or carbon from the quartz and graphite crucible which later will resulted in defects and then lowering the efficiency of Si wafer. The heat transfer plays an important role in the formation of Si ingots. However, the heat transfer generates convection in Si molten state which induces the defects in Si crystal. In this study, a crystal growth simulation software was used to optimize the Si crystal growth process. The furnace and system design were modified. The results showed the melt-crystal interface shape can affect the Si crystal growth rate and defect points. In this study, the defect points and desired interface shape were controlled by specific crystal growth rate condition.

규소 결정 표면의 구조 결함의 형성에 미치는 기계적 손상의 영향

김대일,김종범,김영관,Kim, Dae-Il,Kim, Jong-Bum,Kim, Young-Kwan 한국결정성장학회 2005 한국결정성장학회지 Vol.15 No.2

규소 표면의 기계적 손상은 산화 공정 중에 규소 표면에 여러 가지 형태의 결함들을 발생 시킨다. 규소 표면에 손상을 주는 마모 입자가 커짐에 따라 OISF보다는 etch pit의 형상이 동굴형인 선 결함(line defects)들이 많이 발생된다. 이들 결함들은 실리콘 결정을 성장시키는 단계에서 형성되는 결함들과는 상호 관련이 없다. 방향성 응고법으로 성장된 규소 결정속에 존재하는 결함들은 주로 twin과 stacking fault들이며 응고과정에서 발생이 예상되는 응력에 의한 전위는 거의 발견되지 않았다. 따라서 Czochralski 법으로 성장된 단 결정 규소뿐 아니라 방향성 응고법으로 성장된 다 결정 규소 기판도 표면의 결함들을 이용하여 extrinsic gettering을 통한 규소 결정 내부의 불순물 제거의 가능성이 높다. During oxidation process, several type of defects are formed on the surface of the silicon crystal which was damaged mechanically before oxidation. As the size of abrasive particle increases multiple dislocation loops are produced favorably over oxidation-induced stacking faults, which are dominantly produced when ground with finer abrasive particle. These defects are not related with the crystal growth process like Czochralski or directional solidification. During directional solidification process, twins and stacking faults are the two major defects observed in the bulk of the silicon crystal. On the other hand, slip dislocations produced by the thermal stress are not observed. Thus, not only in single crystalline silicon crystal but also in multi-crystalline silicon, extrinsic gettering process with programmed production of surface defects might be highly applicable to silicon wafers for purification.

Transverse Wave Propagation in [ab0] Direction of Silicon Single Crystal

Sangjin Yun,Hye-Jeong Kim,Seho Kwon,Young H. Kim 한국비파괴검사학회 2015 한국비파괴검사학회지 Vol.35 No.6

The speed and oscillation directions of elastic waves propagating in the [ab0] direction of a silicon single crystal were obtained by solving Christoffel’s equation. It was found that the quasi waves propagate in the off-principal axis, and hence, the directions of the phase and group velocities are not the same. The maximum deviation of the two directions was 7.2°. Two modes of the pure transverse waves propagate in the [110] direction with different speeds, and hence, two peaks were observed in the pulse echo signal. The amplitude ratio of the two peaks was dependent on the initial oscillating direction of the incident wave. The pure and quasi-transverse waves propagate in the [210] direction, and the oscillation directions of these waves are perpendicular to each other. The skewing angle of the quasi wave was calculated as 7.14°, and it was measured as 9.76°. The amplitude decomposition in the [210] direction was similar to that in the [110] direction, since the oscillation directions of these waves are perpendicular to each other. These results offer useful information in measuring the crystal orientation of the silicon single crystal.

Transverse Wave Propagation in [ab0] Direction of Silicon Single Crystal

윤상진,김혜정,권세호,김영환 한국비파괴검사학회 2015 한국비파괴검사학회지 Vol.35 No.6

The speed and oscillation directions of elastic waves propagating in the [ab0] direction of a silicon single crystal were obtained by solving Christoffel’s equation. It was found that the quasi waves propagate in the off-principal axis, and hence, the directions of the phase and group velocities are not the same. The maximum deviation of the two directions was 7.2°. Two modes of the pure transverse waves propagate in the [110] direction with different speeds, and hence, two peaks were observed in the pulse echo signal. The amplitude ratio of the two peaks was dependent on the initial oscillating direction of the incident wave. The pure and quasi-transverse waves propagate in the [210] direction, and the oscillation directions of these waves are perpendicular to each other. The skewing angle of the quasi wave was calculated as 7.14°, and it was measured as 9.76°. The amplitude decomposition in the [210] direction was similar to that in the [110] direction, since the oscillation directions of these waves are perpendicular to each other. These results offer useful information in measuring the crystal orientation of the silicon single crystal.

Liquid-Crystal-on-Silicon 소자에서 액정의 프리틸트각에 따른 Disclination Line 발생

정태봉,오세태,이승희 한국전기전자재료학회 2003 전기전자재료학회논문지 Vol.16 No.4

We have studied how surface pretilt angle affects generation of disclination line in liquid-crystal-on silicon cells for 45$^{\circ}$-twisted nematic (TN) and vertical alignment (VA) modes with pixel size of 15$\mu\textrm{m}$. Our studies show that when the pretilt angle is increased from 0$^{\circ}$to 3$^{\circ}$ in the 45$^{\circ}$-TN cell, the disclination line at left side of on-pixel becomes weak and is well suppressed with $\theta$$\_$p/=3$^{\circ}$ although the pixel size Is decreased. In the VA cell, when the pretilt angle is decreased from 89$^{\circ}$ to 86$^{\circ}$, the disclination line at right side of the on-pixel is suppressed well and even for a smaller pixel size, it does not exist when $\theta$$\_$p/=86$^{\circ}$. The results inform that the pretilt angle strongly affects the image quality of microdisplays.

Transverse Wave Propagation in [ab0] Direction of Silicon Single Crystal

Yun, Sangjin,Kim, Hye-Jeong,Kwon, Seho,Kim, Young H. The Korean Society for Nondestructive Testing 2015 한국비파괴검사학회지 Vol.35 No.6

The speed and oscillation directions of elastic waves propagating in the [ab0] direction of a silicon single crystal were obtained by solving Christoffel's equation. It was found that the quasi waves propagate in the off-principal axis, and hence, the directions of the phase and group velocities are not the same. The maximum deviation of the two directions was $7.2^{\circ}$. Two modes of the pure transverse waves propagate in the [110] direction with different speeds, and hence, two peaks were observed in the pulse echo signal. The amplitude ratio of the two peaks was dependent on the initial oscillating direction of the incident wave. The pure and quasi-transverse waves propagate in the [210] direction, and the oscillation directions of these waves are perpendicular to each other. The skewing angle of the quasi wave was calculated as $7.14^{\circ}$, and it was measured as $9.76^{\circ}$. The amplitude decomposition in the [210] direction was similar to that in the [110] direction, since the oscillation directions of these waves are perpendicular to each other. These results offer useful information in measuring the crystal orientation of the silicon single crystal.

Crystallization of amorphous silicon films via electron beam exposure

문병연,강정수,박선용,박규창 한국정보디스플레이학회 2015 Journal of information display Vol.16 No.3

An electron-beam-induced crystallization technique for amorphous silicon (a-Si:H) thin films was investigated. The high-energy electron beams (e-beams) transfer their energy to the silicon network, resulting in network relaxation and crystallization. The crystalline properties of the silicon film strongly rely on the e-beam exposure time and the acceleration voltage. The crystallinity of the silicon film depends on the a-Si:H growth method used. Silicon films with higher crystallinity can be obtained from thin films deposited via plasma-enhanced chemical vapor deposition (PECVD) rather than from thin films deposited via sputtering. The PECVD silicon thin film showed more than 94% crystallinity and a ∼50 nm grain size after e-beam exposure with 1500 V acceleration bias for 180 s.

Influence mechanism of silicon surface generation in ultraprecision turning

Zhang Shijun 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.4

A quantificational approach was proposed to analyze the discrepancy of monocrystalline silicon surface roughness along different crystal orientations in diamond turning on Statistical Product and Service Solutions software. This work aimed to understand how crystal orientation affects surface generation in the cutting behavior of monocrystalline silicon. In this study, the measured surface roughness data were first processed in advance to eliminate some adverse effects of outliers. The average values of surface roughness distributions were obtained. The surface roughness values of different measurement directions were compared, and the influences of crystal orientations on surface roughness were analyzed. Results indicate that the crystal orientation and the cutting parameters have much influence on machined surface roughness. Finding some special crystal orientations using Euclidean distance analysis with average analysis is effective. The vibration induced by crystallographic orientation is the main reason to make surface nonuniform roughness in single-point diamond turning. This finding is verified by analyzing the surface generation mechanism.