Some of Structural and Morphological Optimization of GaN thin film on Si(100) substrate grown by RF sputter

Abstract

One of important material of III-nitrides can be said to be GaN with direct-wide band gap (similar to 3.4 eV) and many industrial devices such as solar cell, LED has been based on GaN thin film. In this research, we elaborately investigated growth of GaN thin film on Si(100) substrate by RF sputter technique and characterization of the film. We have successfully grown GaN thin film on Si substrate with hexagonal structure which has been confirmed by analysis of X-ray measurements. Also, we obtained structural properties of GaN film by (XRD) X-ray Diffraction measurements depending on different Argon, nitrogen and RF power values. During experiment, the value from 25sccm to 100sccm Argon gas value, the value from Oscan to 4sccm Nitrogen gas value and from 50 watt to 125 watt RF power value has been applied. Among these values, we determined the best film in terms of crystalline structure of film From AVM results, we attained and analyzed average roughness (Ra), maximum peak height (Rp), and maximum depth (Rv) average absolute slope of the profile (Delta a)(degrees) of the films successfully. The film having the lowest roughness (Ra) has been achieved depending on different Argon, nitrogen and RF power values. Atomic Force Microscopy results confirmed that some of the films have homogeneous and uniform structure without any holes and crack; but others has voids referring impurities coming from growth process. 'fo sum up, not only growing GaN thin film on Si substrate has been investigated, but also some of structural and morphological parameters' optimization has been studied, analyzed and the best film was determined in view of varied Argon, nitrogen and RF power values. For future direction, optimization of GaN thin film in detail can enable us to fabricate high quality film; therefore it will helps to improving device technology.