氮化时间对扩镓硅基GaN晶体膜质量的影响

Influence of nitridation time on the quality of GaN films deposited on Ga-diffused Si (111) substrates

采用射频磁控溅射在扩镓硅基上溅射Ga2O3薄膜,然后氮化反应组装GaN晶体膜,并研究氮化时间对薄膜晶体质量的影响。测试结果表明:采用两步法生长得到六方纤锌矿结构的GaN多晶膜,扩镓硅层有效的抑制了硅衬底的氮化和弛豫了GaN与Si衬底的热失配。同时显示:在相同的氮化温度下,晶粒尺寸随氮化时间的增加而增大,薄膜的晶化程度相应的得到提高。

GaN thin films were successfully grown on the Ga-diffused Si (111) substrates throughnitriding Ga2O3 thin films deposited by r.f. magnetron sputtering, and the relationship between nitri-dation time and the crystal quality of the films was investigated. The results reveal that the as-grownfilms are polycrystalline hexagonal GaN with wurtzite structure by the two-step growth method, Ga-diffusion layer effectively avoids nitridation of the Si substrates and relaxes the thermal mismatchbetween GaN and Si substrates. Under the same condition of nitridation temperature, the diameter of GaN grains become larger and the crystal quality of GaN films is improved with the increasing nitrida-tion time.