LEC半绝缘GaAs中EL2缺陷的亚稳性和光恢复效应与深能级缺陷的性质

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

LEC-GaAs中几个重要缺陷中心的研究

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

n型LEC-GaAs中E5能级的研究

于2010-11-23批量导入

LEC GaAs中缺陷的光致发光研究

于2010-11-23批量导入

Semi-insulating GaAs grown in outer space

A semi-insulating GaAs single crystal ingot was grown in a recoverable satellite, within a specially designed pyrolytic boron nitride crucible, in a power-traveling furnace under microgravity. The characteristics of a compound semiconductor single crystal depends fundamentally on its stoichiometry, i.e. the ration of two types of atoms in the crystal. a practical technique for nondestructive and quantitative measuring stoichiometry in GaAs single crystal was used to analyze the space-grown GaAs single crystal. The distribution of stoichiometry in a GaAs wafer was measured for the first time. The electrical, optical and structural properties of the space-grown GaAs crystal were studied systematically, Device fabricating experiments prove that the quality of field effect transistors fabricated from direct ion-implantation in semi-insulating GaAs wafers has a close correlation with the crystal's stoichiometry. (C) 2000 Elsevier Science S.A. All rights reserved.

VGF法生长的低位错掺Si-GaAs单晶的缺陷和性质

研究了垂直梯度凝固法（VGF法）生长的掺Si低阻GaAs单晶材料的晶格缺陷和性质,并将VGF法和LEC法生长的非掺半绝缘GaAs单晶进行了比较.利用A-B腐蚀显微方法比较了两种材料中的微沉积缺陷,对其形成原因进行了分析.利用荧光光谱研究了掺Si-GaAs单晶中Si原子和B原子的占位情况和复合体缺陷.Hall测量结果表明,掺Si低阻VGF-GaAs单晶中存在很强的Si自补偿效应,造成掺杂效率降低.VGF-GaAs单晶生长过程中高的Si掺杂浓度造成晶体中产生大量杂质沉积,而杂质B的存在加重了这种现象.对降低缺陷密度,提高掺杂效率的途径进行了分析.

Semi-insulating GaAs grown in outer space

A semi-insulating GaAs single crystal ingot was grown in a recoverable satellite, within a specially designed pyrolytic boron nitride crucible, in a power-traveling furnace under microgravity. The characteristics of a compound semiconductor single crystal depends fundamentally on its stoichiometry, i.e. the ration of two types of atoms in the crystal. a practical technique for nondestructive and quantitative measuring stoichiometry in GaAs single crystal was used to analyze the space-grown GaAs single crystal. The distribution of stoichiometry in a GaAs wafer was measured for the first time. The electrical, optical and structural properties of the space-grown GaAs crystal were studied systematically, Device fabricating experiments prove that the quality of field effect transistors fabricated from direct ion-implantation in semi-insulating GaAs wafers has a close correlation with the crystal's stoichiometry. (C) 2000 Elsevier Science S.A. All rights reserved.

Relationship between deep-level centers and stoichiometry in semi-insulating gallium arsenide

Experimental results have shown the fact that the deep-level centers in semi-insulating GaAs decrease with the improvement in stoichiometry. The electrical resistivity doubles when the concentration of EL2 centers decreases to a half. The microgravity-growth experiments also show that improved crystal stoichiometry results in a decrease of deep-level centers. (C) 1998 American Institute of Physics. [S0021-8979(98)04921-4].

Numerical Analysis of LEC Growth of GaAs with an Axial Magnetic Field

A set of numerical analyses for momentum and heat transfer For a 3 in. (0.075 m) diameter Liquid Encapsulant Czochralski (LEC) growth of single-crystal GaAs with or without all axial magnetic field was carried Out using the finite-element method. The analyses assume a pseudosteady axisymmetric state with laminar floats. Convective and conductive heat transfers. radiative heat transfer between diffuse surfaces and the Navier-Stokes equations for both melt and encapsulant and electric current stream function equations Cor melt and crystal Lire considered together and solved simultaneously. The effect of the thickness of encapsulant. the imposed magnetic field strength as well as the rotation rate of crystal and crucible on the flow and heat transfer were investigated. (C) 2002 Published by Elsevier Science Ltd.

LEC掺In-GaAs单晶中一种缺陷的研究

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

Numerical analysis of LEC growth of GaAs with an axial magnetic field

A set of numerical analyses for momentum and heat transfer For a 3 in. (0.075 m) diameter Liquid Encapsulant Czochralski (LEC) growth of single-crystal GaAs with or without all axial magnetic field was carried Out using the finite-element method. The analyses assume a pseudosteady axisymmetric state with laminar floats. Convective and conductive heat transfers. radiative heat transfer between diffuse surfaces and the Navier-Stokes equations for both melt and encapsulant and electric current stream function equations Cor melt and crystal Lire considered together and solved simultaneously. The effect of the thickness of encapsulant. the imposed magnetic field strength as well as the rotation rate of crystal and crucible on the flow and heat transfer were investigated. (C) 2002 Published by Elsevier Science Ltd.

INVESTIGATION OF NEGATIVE TRANSIENT CURRENT OF ARGON-IMPLANTED GAAS USING PHOTOINDUCED TRANSIENT-CURRENT SPECTROSCOPY

The investigation of deep levels of argon-implanted LEC-grown semi-insulating GaAs with implantation dosages ranging from 1 x 10(11) to 1 x 10(15) cm-2 has been performed. Using a photoinduced transient-current spectroscopy (PITCS) it was demonstrated that, for implantation dosages below 1 X 10(13) cm-2, a negative peak or negative transient current (NTC) was observed in the temperature range from 330 to 350 K. The magnitude of this negative peak increased with dosage up to a level of 1 X 10(12) cm-2, beyond which it decreased with dosage. The dosage dependence of the EL3 peak height and the resistance of the specimen have also been investigated. It was observed that the variation of the EL3 peak height with dosage was similar to the variation of the magnitude of the negative peak, that is the EL3 peak height likewise increased with dosage up to 1 X 10(12) cm-2, and then decreased. The resistance of the original high-resistivity specimen dropped abruptly when the dosage reached 1 X 10(12) cm-2. This critical dosage (1 X 10(12) cm-2) was found to be a threshold for the generation of a highly disordered state.

Stoichiometric defects in semi-insulating GaAs

The influences of arsenic interstitials and dislocations on the lattice parameters of undoped semi-insulating (SI) GaAs single crystals were analyzed. It was shown that the dislocations in such crystals serve as effective gettering sites for arsenic interstitials due to the deformation energy of dislocations. The average excess arsenic in GaAs epilayers grown by molecular-beam epitaxy (MBE) at low temperatures (LT) is about 1%, and the lattice parameters of these epilayers are larger than those of liquid-encapsulated Czochralski-grown (LEG) SI-GaAs by about 0.1%. The atomic ratio, [As]/([Ga] + [As]), in SI-GaAs grown by low-pressure (LP) LEC is the nearest to the strict stoichiometry compared with those grown by high-pressure (HP) LEC and vertical gradient freeze (VGF). After multiple wafer annealing (MWA), the crystals grown by HPLEC become closer to be strictly stoichiometric.

高温退火处理提高半绝缘VGF-GaAs单晶的电学性能

垂直梯度凝固法（VGF）生长的低位错半绝缘（SI）GaAs单晶存在电阻率和迁移率低、电学补偿度小、均匀性差等问题.在3种不同温度条件下,对VGF-SI-GaAs晶片进行了加As压的闭管退火处理.结果表明,经过1160℃/12h的高温退火处理后,VGF-SI-GaAs单晶的电阻率、迁移率和均匀性均得到了显著提高.利用Hall、热激电流谱（TSC）、红外吸收法分别测试分析了原生和退火VGF-SI-GaAs单晶样品的电学性质、深能级缺陷、EL2浓度和C浓度,并与常规液封直拉法（LEC）SI-GaAs单晶样品进行了比较.原生VGF-SI-GaAs单晶中的EL2浓度明显低于LEC-SI-GaAs单晶,经过退火处理后其EL2浓度显著增加,电学补偿增强,而且能级较浅的一些缺陷的浓度降低,因而有效提高了其电学性能.