The SIMS Study Of C、H、O Pollution In LED Epitaxial Layer On Si Substrate

This article gives a research on the ways to improve the influence that adsorption air samples laid on Secondary Ion Mass Spectrometer (SIMS) quantitative analysis C, H, O and research on that SIMS quantitative analysis C, H, O influenced by number of elements to improve the accuracy of SIMS’s quantitative analysis to C, H, O; in the meantime, it gives a further research on the influence that growing conditions of MOCVD(NH3flow) has on C, H, O pollution in GaN materials and AIN materials with the help of SIMS. Besides, this article gives a research on the elements distribution’s homogeneity of C, H, O of buffer layer (AIN, AlGaN) over Si substratum in this experiment, which finally yielded the following results to have provided reliable basis on epitaxial growth of my laboratory:(1)To place the samples in the SIMS samples cavity and vacuumize it, and found that the sample absorbed air had decreasing influence on SIMS’s quantitative analysis to elements C, H, O with more pumping time to ultimately eliminate this influence(This process will take a long time); SIMS by adding liquid nitrogen in liquid nitrogen cold trap to overcome the influence on SIMS’s quantitative analysis to elements C, H, O is limited,which cased by sample absorbed air, But it can assist the former, Reducing the time required for vacuum and Improving the efficiency.(2)The SIMS curve’s depth resoulth of elements C, H, O gets higher when less elements analyzed simutaneously by SIMS.(3)The quantity of C in GaN material (C Pollution) decreases with the increase of ammonia flow to develops a power function relationship; while the quantity of H impurity and O impurity in GaN material has no obvious changes with the increase of ammonia flow; in the meantime, the growth of GaN material gets slower with the increase of ammonia flow.(4)The quantity of C in AIN material (C Pollution) increases with the increase of ammonia flow, adverse to the relationship between the quantity of C in GaN material (C Pollution) and ammonia flow. The quantity of H impurity and O impurity in AIN material increase along with the increase of ammonia flow, dissimilar to the relationship between the quantity of H impurity and O impurity in GaN material and ammonia flow. (5)The distribution of element C, H grow in the buffer layer (AIN, AIGaN) over the Si substratum is extremely uniformed, whereby element O distributes less uniformed inside.