采用ECR-PEMOCVD方法进行立方和六方GaN单晶薄膜生长的准热力学模型和相图

基于热力学平衡理论,对在电子回旋共振等离子体增强金属有机化学气相沉积系统中的GaN薄膜生长给出了一个化学平衡模型.计算表明,GaN生长的驱动力Δp是以下生长条件的函数:Ⅲ族输入分压,输入Ⅴ/Ⅲ比,生长温度.计算了六方和立方GaN的生长相图,计算结果和我们的实验结果显示出一定的一致性.通过分析,解释了高温和高Ⅴ/Ⅲ比生长条件适合六方GaN的原因.上述模型可以延伸到用于GaN单晶薄膜生长的类似系统中.

Thermodynamic Modeling and Phase Diagrams of Hexagonal and Cubic GaN Single-Crystal Film Growth by ECR-PEMOCVD Method

Based on thermodynamic equilibrium theory,a chemical equilibrium model for GaN growth is given in electron cyclotron resonance plasma enhanced metalorganic chemical vapor deposition (ECR-PEMOCVD) system.Calculation indicates that the growth driving force are functions of growth conditions:group Ⅲ input partial pressure,input Ⅴ/Ⅲ ratio,and growth temperature.Furthermore,the growth phase diagrams of hexagonal and cubic GaN film growth are obtained,which are consistent with our experimental conditions to some extent.Through analysis,it is explained the reason that high temperature and high input Ⅴ/Ⅲ ratio are favorable for hexagonal GaN film growth.This model can be extended to the similar systems used for GaN single-crystal film growth.