Development of a High Rate 4H-SiC Epitaxial Growth Technique Achieving Large-Area Uniformity

2008 ◽  
Vol 600-603 ◽  
pp. 111-114 ◽  
Author(s):  
Masahiko Ito ◽  
L. Storasta ◽  
Hidekazu Tsuchida
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Free Exciton ◽  
High Growth ◽  
Maximum Growth ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
High Rate ◽  
Intrinsic Defect ◽  
Large Area

A vertical hot-wall type epi-reactor that makes it possible to simultaneously achieve both a high rate of epitaxial growth and large-area uniformity at the same time has been developed. A maximum growth rate of 250 µm/h is achieved at 1650 °C. Thickness uniformity of 1.1 % and doping uniformity of 6.7 % for a 65 mm radius area are achieved while maintaining a high growth rate of 79 µm/h. We also succeeded in growing a 280 µm-thick epilayer with excellent surface morphology and long carrier lifetime of ~1 µs on average. The LTPL spectrum shows free exciton peaks as dominant, and few impurity-related or intrinsic defect related peaks are observed. The DLTS measurement for an epilayer grown at 80 µm/h shows low trap concentrations of 1.2×1012 cm-3 for Z1/2 center and 6.3×1011 cm-3 for EH6/7 center, respectively.

Dynamics of Exploited Whitefish Populations and their Management with Special Reference to the Northwest Territories

1975 ◽  
Vol 32 (3) ◽  
pp. 427-448 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
Growth Rate ◽  
Population Size ◽  
Total Mortality ◽  
High Growth ◽  
Maximum Growth ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
Stock Size ◽  
Slow Growth Rate ◽  
Wide Range

Available data on mortality, growth, reproduction, and stock size in exploited and unexploited populations of lake whitefish (Coregonus clupeaformis) are reviewed with a view to understanding the dynamics of exploited populations and improving their management. Natural mortality ranged from about 0.20 to 0.80 in unexploited populations. In exploited populations total mortality was as high as 0.94. Unexploited populations showed a wide range of growth rates. Growth rate increased with increasing exploitation, and growth rate in all heavily exploited populations was similar to the most rapid growth rate shown by unexploited stocks. Heavily exploited whitefish matured at a younger age and possibly also at a smaller size than those which were unexploited. Limited data on stock size suggest that although total population size declines under heavy exploitation, the vulnerable population remains of similar size.It is concluded that whitefish respond to fluctuations in population size through compensatory changes in growth rate, the difference between growth rate in a population and maximum growth rate is a measure of its scope for compensating for increased mortality. Populations with slow growth rate and low mortality should, therefore, have the best fishery potential, while those with high growth rate and high mortality have a low fishery potential. Further, it is possible to judge the fishery potential of a population or its stage of exploitation from relatively simple measurements of mortality, growth, age structure, and maturity.

scholarly journals Influence of types of constitution on meat productivity bullets of Simmental breed

2021 ◽  
Vol 273 ◽  
pp. 02024
Author(s):  
Anatoly Shevkhuzhev ◽  
Vladimir Pogodaev ◽  
Dagir Smakuev
Keyword(s):  
Growth Rate ◽  
Beef Cattle ◽  
Meat Products ◽  
Live Weight ◽  
High Growth ◽  
Maximum Growth ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
Cattle Breeding ◽  
Meat Productivity

The aim of the research was to establish quantitative and qualitative indicators of meat productivity of Simmental bull calves of various constitutional types when raised using the technology of beef cattle breeding. The maximum growth rate and the highest yield of meat products were obtained from Simmental bulls of the meat and dairy type when they were raised and fed according to the technology of beef cattle breeding. Receiving from the mothers for 205 days of the sucking period more fatty milk, they gave 1250 g of gain per day and reached 289.7 kg of live weight by the cut. Having retained a high growth rate in the future, they at the final fattening gave 1321 g of gain per day and at 20 months the live weight was 659.3 kg. The superiority of Simmentals over analogues was natural by 3.4–13.3% by weight of the steamed carcass, by 0.4–1.8% in slaughter yield, by 1.4–11.1 kg in terms of the amount of pulp in the carcass and pulp per bones by 0.1–0.3 kg, protein in meat by 0.12; 1.19; 2.59 kg and the amount of energy in the pulp by 0.14; 0.44; 1.75 MJ. Simmental bulls of the meat and dairy type also have a high ability to transform protein and feed energy into protein and energy from the pulp of the carcass.

The Annual Growth-Rate Cycle in Brown Trout (Salmo Trutta Linn.) and Its Cause

1961 ◽  
Vol 38 (3) ◽  
pp. 595-604
Author(s):  
D. R. SWIFT
Keyword(s):  
Growth Rate ◽  
Brown Trout ◽  
Salmo Trutta ◽  
High Growth ◽  
Maximum Growth ◽  
Field Work ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
Annual Growth ◽  
Annual Growth Rate

1. A regular annual growth-rate cycle is demonstrated in wild and hatchery yearling brown trout; the fish have a high growth rate in the spring and autumn and a low growth rate during the summer and winter of each year. 2. Experimental work with constant-environment aquaria, together with the results of the field work, indicate that the water temperature is the main external environmental factor influencing the growth rate. Maximum growth rate is achieved at 12° C. 3. The reason for the fall in growth rate above 12° C. is discussed and it is suggested that inadequacy of the respiratory system of the fish is the prime cause.

Development of High Growth Rate SiC Epi-Reactor with Controlled Thermal Gradient

2007 ◽  
Vol 556-557 ◽  
pp. 81-84
Author(s):  
Masahiko Ito ◽  
Hidekazu Tsuchida ◽  
Isaho Kamata ◽  
L. Storasta
Keyword(s):  
Growth Rate ◽  
Thermal Gradient ◽  
Gas Flow ◽  
Flow Behavior ◽  
High Growth ◽  
Maximum Growth ◽  
High Growth Rate ◽  
Maximum Growth Rate ◽  
Simulation Results ◽  
Growth Experiments

A vertical hot-wall type reactor, with a unique structure designed for controlling both gas flow behavior and thermal gradient (T/mm) on the susceptor surface, was developed. The simulation results indicate that depending on the height of the epitaxy room (h), the T/mm can be changed from a negative to a positive value. Preliminary epitaxial growth experiments resulted in a maximum growth rate of 51 μm/h, 4-inch area uniformity of σ/mean=1.7% for growth rate and σ/mean=21.5 % for doping concentration, and Z1/2 trap concentration of 9×1012 cm-3 at a growth rate of 43 μm/h.

Deposition of large area high quality diamond wafers with high growth rate by DC arc plasma jet

2000 ◽  
Vol 9 (9-10) ◽  
pp. 1673-1677 ◽  
Author(s):  
H. Guo ◽  
Z.L. Sun ◽  
Q.Y. He ◽  
S.M. Du ◽  
X.B. Wu ◽  
...  
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
Plasma Jet ◽  
High Growth Rate ◽  
Arc Plasma ◽  
Large Area ◽  
High Quality ◽  
Dc Arc

Control of Materials and Interfaces in μc-Si:H-based Solar Cells Grown at High Rate

2011 ◽  
Vol 1321 ◽  
Author(s):  
Yasushi Sobajima ◽  
Chitose Sada ◽  
Akihisa Matsuda ◽  
Hiroaki Okamoto
Keyword(s):  
Growth Rate ◽  
Solar Cells ◽  
Film Growth ◽  
Defect Density ◽  
Density Measurement ◽  
High Growth ◽  
High Growth Rate ◽  
High Rate ◽  
Bulk Region ◽  
Dangling Bond

ABSTRACTGrowth process of microcrystalline silicon (μc-Si:H) using plasma-enhanced chemicalvapor- deposition method under high-rate-growth condition has been studied for the control of optoelectronic properties in the resulting materials. We have found two important things for the spatial-defect distribution in the resulting μc-Si:H through a precise dangling-bond-density measurement, e. g., (1) dangling-bond defects are uniformly distributed in the bulk region of μc- Si:H films independent of their crystallite size and (2) large number of dangling bonds are located at the surface of μc-Si:H especially when the film is deposited at high growth rate. Starting procedure of film growth has been investigated as an important process to control the dangling-bond-defect density in the bulk region of resulting μc-Si:H through the change in the electron temperature by the presence of particulates produced at the starting period of the plasma. Deposition of Si-compress thin layer on μc-Si:H grown at high rate followed by thermal annealing has been proposed as an effective method to reduce the defect density at the surface of resulting μc-Si:H. Utilizing the starting-procedure-controlling method and the compress-layerdeposition method together with several interface-controlling methods, we have demonstrated the fabrication of high conversion-efficiency (9.27%) substrate-type (n-i-p) μc-Si:H solar cells whose intrinsic μc-Si:H layer is deposited at high growth rate of 2.3 nm/sec.

scholarly journals The danger of high growth combined with a large non-cash working capital base: A descriptive analysis

2002 ◽  
Vol 33 (1) ◽  
pp. 41-47
Author(s):  
W. Steyn ◽  
W. D. Hamman ◽  
E. V.D.M. Smit
Keyword(s):  
Growth Rate ◽  
Cash Flow ◽  
Descriptive Analysis ◽  
High Growth ◽  
High Growth Rate ◽  
High Rate ◽  
Working Capital ◽  
Net Profit ◽  
A Company ◽  
Operating Activities

A high growth rate may not be the ultimate measure of a successful company. This article shows that growth at too high a rate, for a company with a high non-cash working capital component, may lead to financial difficulties.While the income statement of a company is based on the accrual of income and expenses, the cash flow statement is based on the receipt and payment of cash. A company experiencing high sales growth, depending on the extent of its non-cash working capital, will find that the cash flow from operating activities before the payment of dividends will not grow as quickly as the net profit after taxation. This is because the accrual part included in the net profit after taxation is also growing at a high rate. At such a growth rate, operating activities do not generate sufficient cash to sustain the day-to-day activities of the company.

The assessment of seasonal yield using some Stylosanthes guyanensis accessions in humid tropical and sub-tropical environments

1977 ◽  
Vol 17 (86) ◽  
pp. 425 ◽  
Author(s):  
LA Edye ◽  
WT Williams ◽  
RL Burt ◽  
B Grof ◽  
SL Stillman ◽  
...  
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
Growth Period ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Growth Patterns ◽  
Seasonal Growth ◽  
Seasonally Dry ◽  
Tropical Environments ◽  
Dry Tropics

The seasonal growth patterns of some S. guyanensis accessions were compared in three humid environments at South Johnstone (extended rainfall tropics), 'Heathlands' (seasonally dry tropics) and Cooroy (humid sub-tropics). The accessions were selected mainly for their productivity in previously described small mown sward experiments over three years at each site. Previous methods of presenting seasonal growth patterns are reviewed, and a new, simpler method of presentation is defined. Growth was highly seasonal at all sites. There was no growth during July to November at 'Heathlands' and Cooroy due to moisture and temperature limitations respectively. At South Johnstone growth was continuous but depressed in August and December with limitations due to both soil moisture and temperature: the maximum growth rate was 22 times the minimum growth rate. The accessions differed markedly in their growth patterns at each site. In general, the yield differences between accessions were greater at the beginning and end of the growing season than during the peak growth period. The highest yielding accessions at each site had high growth rates spread over a long period. The yield distribution and persistence of Q8231 and 46589C seemed superior to existing cultivars in tropical and sub-tropical environments respectively

Analysis and Reduction of Stacking Faults in Fast Epitaxial Growth

2016 ◽  
Vol 858 ◽  
pp. 173-176 ◽  
Author(s):  
Hideyuki Uehigashi ◽  
Keisuke Fukada ◽  
Masahiko Ito ◽  
Isaho Kamata ◽  
Hiroaki Fujibayashi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Rate ◽  
Epitaxial Growth ◽  
Stacking Faults ◽  
High Growth ◽  
High Growth Rate ◽  
X Ray ◽  
Crystalline Defects ◽  
Transmission Electron

We have developed a single-wafer vertical epitaxial reactor which realizes high-throughput production of 4H-SiC epitaxial layer (epilayer) with a high growth rate [1,2]. In this paper, in order to evaluate the crystalline defects which can affect the characteristics of devices, we investigated the formation of variety of in-grown stacking faults (SFs) in detail. Synchrotron X-ray topography, photoluminescence (PL) and transmission electron microscopy are employed to analyze the SFs and the origins of the SF formation are discussed. The result in reducing in-grown SFs in fast epitaxial growth is also shown.

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