HVPE法生长AlN薄膜材料

利用自制立式HVPE设备,在蓝宝石衬底上进行了不同载气情况下AlN的生长试验,生长温度1 000℃。在采用H2作载气情况下,由于预反应严重,没能生长出AlN薄膜,只得到一些白色AlN粉末;而在分别采用Ar和N2作载气的情况下,则成功生长出AlN薄膜,但由于生长温度低,AlN生长均为岛状生长模式。在生长速率较快时,AlN薄膜是以〈0001〉AlN为主的AlN多晶;而在较低生长速率下,得到的AlN薄膜由为〈0001〉取向的AlN岛组成。试验还发现:用Ar作载气更有利于AlN晶核的横向生长,用N2作载气则有相对高得多的AlN成核密度。

Growth of AlN Film by HVPE Method

AlN was grown on sapphire substrates with different carrier gases in a self-made HVPE system,and the growth temperature was 1 000 ℃.There was no AlN film besides some white AlN powder on the substrate due to the serious pre-reaction when H2 was used as the carrier gas.The AlN film was obtained by using Ar and N2 as carrier gases.However,the AlN film was grown in Volmer-Weber mode because of the low growth temperature.The AlN film was polycrystalline AlN with 〈0001〉 main crystallographic direction at a higher growth rate,while the AlN film was composed of highly oriented 〈0001〉 AlN islands at a lower growth rate.The experiment shows that the carrier gas Ar is beneficial to the lateral growth of the nucleation islands,and the carrier gas N2 is favorable for nucleation islands with higher density.