Effect of growth‐rate ratio on surface morphology of homoepitaxial diamond (100) and (111)

1996 ◽  
Vol 69 (26) ◽  
pp. 4032-4034 ◽  
Author(s):  
Robin E. Rawles ◽  
William G. Morris ◽  
Mark P. D’Evelyn
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Rate Ratio

Growth rate, surface morphology, and defect microstructures of β–SiC films chemically vapor deposited on 6H–SiC substrates

1989 ◽  
Vol 4 (1) ◽  
pp. 204-214 ◽  
Author(s):  
H. S. Kong ◽  
J. T. Glass ◽  
R. F. Davis
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Flow Rate ◽  
Rate Ratio ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Flow Rate Ratio ◽  
Gas Flow Rate ◽  
Carrier Gas ◽  
Carrier Gas Flow

Beta–SiC thin films have been epitaxially grown on 6H–SiC {0001} substrates via chemical vapor deposition (CVD). The growth rate increased linearly with the source/carrier gas flow rate ratio. The activation energy for the growth of β–SiC grown on the Si face of the 6H–SiC substrate was 12 Kcal/mole. These observations are consistent with a surface reaction-controlled process. The as-grown surface morphology is dependent on the terminal layer of the substrate, the growth temperature, and the source/carrier gas flow rate ratio. The C face of a 6H–SiC {0001} substrate caused a higher growth rate and thus poorer surface morphology than the Si face under the same growth conditions. The optimum temperature range for growth of a flat, mirror-like β–SiC surface was determined to be 1773–1823 K in the present CVD system. The microstructure and nucleation of double positioning boundaries were investigated via transmission and scanning electron microscopies. Triangular defects and their modifications were also observed, and their origins have been discussed.

ФОРМИРОВАНИЕ ПЕРЕХОДНОГО СЛОЯ ALN НА ТЕМПЛЕЙТАХ 3С-SIC/SI(111) МЕТОДОМ АММИАЧНОЙ МОЛЕКУЛЯРНО-ЛУЧЕВОЙ ЭПИТАКСИИ

2020 ◽  
Vol 96 (3s) ◽  
pp. 148-153
Author(s):  
С.Д. Федотов ◽  
А.В. Бабаев ◽  
В.Н. Стаценко ◽  
К.А. Царик ◽  
В.К. Неволин
Keyword(s):  
Crystal Structure ◽  
Growth Rate ◽  
Low Temperature ◽  
Surface Morphology ◽  
Single Crystal ◽  
Root Mean Square Roughness ◽  
Rate Variation ◽  
Mean Square ◽  
Nucleation Layer ◽  
Low Temperature Epitaxy

Представлены результаты изучения морфологии поверхности и структуры слоев AlN, сформированных аммиачной МЛЭ на темплейтах 3C-SiC/Si(111) on-axis- и 4° off-axis-разориентации. Опробован технологический режим низкотемпературной эпитаксии зародышевого слоя AlN на поверхности 3C-SiC(111). Среднеквадратичная шероховатость поверхности (5 х 5 мкм) слоев AlN толщиной 150 ± 50 нм составила 2,5-3,5 нм на темплейтах 3C-SiC/Si(111) on-axis и 3,3-3,5 нм на 4° off-axis. Показано уменьшение шероховатости смачивающего слоя AlN при изменении скорости роста. Получены монокристаллические слои AlN(0002) со значениями FWHM (ω-геометрия) 1,4-1,6°. The paper presents the surface morphology and crystal structure of AlN layers formed by ammonia MBE on 3C-SiC/Si(111) on-axis and 4° off-axis disorientation. It offers the technological approach of low-temperature epitaxy of the AlN nucleation layer on the 3C-SiC (111) surface. Root mean square roughness (5 х 5 |xm) of AlN layers with thickness of 150 ± 50 nm was 2,5-3,5 nm onto on-axis templates and 3.3-3.5 nm onto 4° off-axis. It appears that the RMS roughness of the AlN surface is changing with the growth rate variation. Single-crystal AlN(0002) layers with FWHM values (ω-geometry) of 1.4-1.6° have been obtained.

Growth Rate and Surface Morphology of Diamond Homoepitaxial Films on Misoriented (001) Substrates

1996 ◽  
Vol 35 (Part 1, No. 9A) ◽  
pp. 4724-4727 ◽  
Author(s):  
Takashi Tsuno ◽  
Hiromu Shiomi ◽  
Yoshiaki Kumazawa ◽  
Shin-ichi Shikata ◽  
Shin-ichi Akai
Keyword(s):  
Growth Rate ◽  
Surface Morphology

Growth rate and surface morphology of 4H–SiC crystals grown from Si–Cr–C and Si–Cr–Al–C solutions under various temperature gradient conditions

2014 ◽  
Vol 401 ◽  
pp. 681-685 ◽  
Author(s):  
Takeshi Mitani ◽  
Naoyoshi Komatsu ◽  
Tetsuo Takahashi ◽  
Tomohisa Kato ◽  
Kuniharu Fujii ◽  
...  
Keyword(s):  
Growth Rate ◽  
Temperature Gradient ◽  
Surface Morphology

Homoepitaxial Growth on Si-Face (0001) On-Axis 4H-SiC Substrates

2019 ◽  
Vol 954 ◽  
pp. 31-34
Author(s):  
Guo Guo Yan ◽  
Xing Fang Liu ◽  
Feng Zhang ◽  
Zhan Wei Shen ◽  
Wan Shun Zhao ◽  
...  
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Epitaxial Growth ◽  
Growth Temperature ◽  
Epitaxial Layers ◽  
Homoepitaxial Growth ◽  
Influence Mechanism

Homoepitaxial growths of 4H-SiC were performed on Si-face (0001) on-axis substrates in a SiH4-C2H4-H2-HCl system by using our home-made vertical hot wall CVD reactor. The influence mechanism of the growth temperature and C/Si ratio on the morphology and growth rate was studied. It is found that the steps in the epilayer become more clear with the increasing temperatures. The result indicates that the C/Si ratio window of on-axis epitaxial growth is very narrow. Only when the C/Si ratio was 1.2, a slightly improved surface morphology can be achieved. The results indicate that 4H-SiC epitaxial layers were obtained on on-axis substrates and the films were highly-oriented 4H-SiC.

Improvements of the Continuous Feed-Physical Vapor Transport Technique (CF-PVT) for the Seeded Growth of 3C-SiC Crystals

2010 ◽  
Vol 645-648 ◽  
pp. 63-66 ◽  
Author(s):  
Guoli L. Sun ◽  
Irina G. Galben-Sandulache ◽  
Thierry Ouisse ◽  
Jean Marc Dedulle ◽  
Michel Pons ◽  
...  
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
High Growth ◽  
High Growth Rate ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Seeded Growth ◽  
Grown Layer ◽  
Continuous Feed ◽  
Transport Technique

The Continuous Feed-Physical Vapor Transport Technique (CF-PVT) was optimized by considering the heating, thermal insulation and the geometry of growth cavity. The effects of seeds on the surface morphology of the grown layer have been discussed. We successfully grew 3C-SiC bulk with a diameter of 7.0 mm and 3.3 mm in height with a high growth rate of 0.8 mm/h by the CF-PVT technique.

Surface Morphology of AlN Epitaxial Layer Grown on Various SiC Substrates by Sublimation Closed Space Technique

2008 ◽  
Vol 600-603 ◽  
pp. 1285-1288
Author(s):  
Gi Sub Lee ◽  
Myung Ok Kyun ◽  
Hyun Hee Hwang ◽  
Joon Ho An ◽  
Won Jae Lee ◽  
...  
Keyword(s):  
Growth Rate ◽  
Surface Morphology ◽  
Epitaxial Layer ◽  
Growth Time ◽  
Closed Space ◽  
Polycrystalline Structure ◽  
Average Growth Rate ◽  
Average Growth ◽  
Epitaxial Structure ◽  
Space Technique

A sublimation epitaxial method, referred to as the Closed Space Technique (CST) was adopted to produce AlN epitaxial layers. In this study, we report the surface morphology of AlN epitaxial layer grown on various substrates such as 3C-SiC (100), 4H-SiC (0001) with 8o off-axis (0001) plane tilted toward the <11 2 0> direction and on-axis 4H-SiC (0001). An average growth rate of AlN layer at 2350oC in 500 Torr of N2 was measured to be about 6μm/hr. While AlN layer grown on the 3C-SiC (100) substrate at 2350oC exhibited polycrystalline structure, AlN epitaxial layer grown on on-axis and off-axis 4H-SiC (0001) substrates had highly c-axis oriented epitaxial structure. In particular, the stacked structure of hexagonal plates was observed on off-axis substrate and the size of the hexagonal plates increased with growth time. Hexagonal plates were observed to be coalesced and the step-bunching was finally disappeared.

scholarly journals The mobility gap: estimating mobility levels required to control Canada’s winter COVID-19 surge

2021 ◽  
Author(s):  
Kevin A. Brown ◽  
Jean-Paul R. Soucy ◽  
Sarah A. Buchan ◽  
Shelby L. Sturrock ◽  
Isha Berry ◽  
...  
Keyword(s):  
Growth Rate ◽  
Residential Mobility ◽  
Rate Ratio ◽  
Herd Immunity ◽  
Primary Means ◽  
Low Levels ◽  
The Difference ◽  
Canadian Provinces ◽  
Pharmaceutical Interventions ◽  
Mobility Gap

AbstractBackgroundNon-pharmaceutical interventions remain a primary means of suppressing COVID-19 until vaccination coverage is sufficient to achieve herd immunity. We used anonymized smartphone mobility measures in seven Canadian provinces to quantify the mobility level needed to suppress COVID-19 (mobility threshold), and the difference relative to current mobility levels (mobility gap).MethodsWe conducted a longitudinal study of weekly COVID-19 incidence from March 15, 2020 to January 16, 2021, among provinces with 20 COVID-19 cases in at least 10 weeks. The outcome was weekly growth rate defined as the ratio of current cases compared to the previous week. We examined the effects of average time spent outside the home (non-residential mobility) in the prior three weeks using a lognormal regression model accounting for province, season, and mean temperature. We calculated the COVID-19 mobility threshold and gap.ResultsAcross the 44-week study period, a total of 704,294 persons were infected with COVID-19. Non-residential mobility dropped rapidly in the spring and reached a median of 36% (IQR: 31,40) in April 2020. After adjustment, each 5% increase in non-residential mobility was associated with a 9% increase in the COVID-19 weekly growth rate (ratio=1.09, 95%CI: 1.07,1.12). The mobility gap increased through the fall months, which was associated with increasing case growth.InterpretationMobility strongly and consistently predicts weekly case growth, and low levels of mobility are needed to control COVID-19 through winter 2021. Mobility measures from anonymized smartphone data can be used to guide the provincial and regional implementation and loosening of physical distancing measures.

LPE Growth of Textured KNbO3 Film Using SrTiO3 Substrate and V2O5 Flux

2006 ◽  
Vol 11-12 ◽  
pp. 109-112
Author(s):  
T. Hibino ◽  
Kenichi Kakimoto ◽  
Hitoshi Ohsato
Keyword(s):  
Thin Films ◽  
Phase Diagram ◽  
Growth Rate ◽  
Liquid Phase ◽  
Surface Morphology ◽  
Liquid Phase Epitaxy ◽  
Growth Temperature ◽  
Film Growth ◽  
Lower Growth ◽  
Lower Growth Temperature

KNbO3 thin films were grown on (100) and (110) SrTiO3 substrates by liquid phase epitaxy (LPE) technique. The film orientation and surface morphology were characterized by XRD and AFM, respectively. The limited phase diagram of K2O-Nb2O5-V2O5 system was prepared by DTA measurement to investigate the effect of V2O5 flux on the LPE growth of KNbO3 film. The use of V2O5 flux enhanced a film growth rate at lower growth temperature.

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