Controlled growth of semiconductor crystals
Abstract
A method is disclosed for growth of III-V, II-VI and related semiconductor single crystals that suppresses random nucleation and sticking of the semiconductor melt at the crucible walls. Small pieces of an oxide of boron B[sub x]O[sub y] are dispersed throughout the comminuted solid semiconductor charge in the crucible, with the oxide of boron preferably having water content of at least 600 ppm. The crucible temperature is first raised to a temperature greater than the melt temperature T[sub m1] of the oxide of boron (T[sub m1]=723 K for boron oxide B[sub 2]O[sub 3]), and the oxide of boron is allowed to melt and form a reasonably uniform liquid layer between the crucible walls and bottom surfaces and the still-solid semiconductor charge. The temperature is then raised to approximately the melt temperature T[sub m2] of the semiconductor charge material, and crystal growth proceeds by a liquid encapsulated, vertical gradient freeze process. About half of the crystals grown have a dislocation density of less than 1000/cm[sup 2]. If the oxide of boron has water content less than 600 ppm, the crucible material should include boron nitride, a layer of the inner surface of the crucible should be oxidized before the oxide ofmore »
- Inventors:
- Issue Date:
- OSTI Identifier:
- 7205481
- Patent Number(s):
- 5131975
- Application Number:
- PPN: US 7-551433
- Assignee:
- Univ. of California, Oakland, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- Resource Type:
- Patent
- Resource Relation:
- Patent File Date: 10 Jul 1990
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; SEMICONDUCTOR MATERIALS; CRYSTAL GROWTH; BORON OXIDES; DISLOCATIONS; MELTING POINTS; MONOCRYSTALS; BORON COMPOUNDS; CHALCOGENIDES; CRYSTAL DEFECTS; CRYSTAL STRUCTURE; CRYSTALS; LINE DEFECTS; MATERIALS; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; THERMODYNAMIC PROPERTIES; TRANSITION TEMPERATURE; 360601* - Other Materials- Preparation & Manufacture
Citation Formats
Bourret-Courchesne, E D. Controlled growth of semiconductor crystals. United States: N. p., 1992.
Web.
Bourret-Courchesne, E D. Controlled growth of semiconductor crystals. United States.
Bourret-Courchesne, E D. Tue .
"Controlled growth of semiconductor crystals". United States.
@article{osti_7205481,
title = {Controlled growth of semiconductor crystals},
author = {Bourret-Courchesne, E D},
abstractNote = {A method is disclosed for growth of III-V, II-VI and related semiconductor single crystals that suppresses random nucleation and sticking of the semiconductor melt at the crucible walls. Small pieces of an oxide of boron B[sub x]O[sub y] are dispersed throughout the comminuted solid semiconductor charge in the crucible, with the oxide of boron preferably having water content of at least 600 ppm. The crucible temperature is first raised to a temperature greater than the melt temperature T[sub m1] of the oxide of boron (T[sub m1]=723 K for boron oxide B[sub 2]O[sub 3]), and the oxide of boron is allowed to melt and form a reasonably uniform liquid layer between the crucible walls and bottom surfaces and the still-solid semiconductor charge. The temperature is then raised to approximately the melt temperature T[sub m2] of the semiconductor charge material, and crystal growth proceeds by a liquid encapsulated, vertical gradient freeze process. About half of the crystals grown have a dislocation density of less than 1000/cm[sup 2]. If the oxide of boron has water content less than 600 ppm, the crucible material should include boron nitride, a layer of the inner surface of the crucible should be oxidized before the oxide of boron in the crucible charge is melted, and the sum of thicknesses of the solid boron oxide layer and liquid boron oxide layer should be at least 50 [mu]m. 7 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1992},
month = {7}
}