非掺半绝缘GaAs单晶的垂直梯度凝固生长

VERTICAL GRADIENT FREEZE GROWTH OF UNDOPED SEMI-INSULATING GaAs CRYSTALS

研究了非掺GaAs半绝缘单晶的液封垂直梯度凝固法(VGF)生长技术,解决了Si沾污和C浓度的控制问题,得到了直径2英寸非掺半绝缘低位错单晶。测试表明:该单晶的位错密度较LEC单晶下降近一个数量级,电学参数与LEC单晶类似,接近国外VGF单晶的参数指标。

Total liquid encapsulated vertical gradient freeze (VGF) method has been used to grow undoped semi-insulating (SI) GaAs crystals. The impurities such as silicon and carbon have been well controlled in the growth process. As a result, a 2' diameter undoped SI GaAs single crystal was achieved. Materials characterization tests demonstrated the Hall parameters of the crystal close to that of LEC crystal, and dislocation densities of 8600cm-2, about one order of magnitude lower than dislocation densities of LEC crystals.