活性化離子蝕刻Ⅲ-Ⅴ化合物半導體

Abstract

本論文是利用活性化離子蝕刻系統,在 BCl3/Ar 電漿中蝕刻 III-V 化合物,並選擇 最佳的蝕刻條件,與穩定的光罩材料. 由輸入功率與 BCl3/(Ar+BCl3)的比例對蝕刻速率的關係可得知,蝕刻鍵結較強的材料時, 需要較高濃度的離子撞擊.在 Ar 比例較高的條件下,不但有助於蝕刻速率 的增加,而且在蝕刻表面及壁面陡峭性上皆能獲得較佳的結果. 此外, 在低壓下進行蝕刻,不但可以提供較高濃度的離子與乾淨的蝕刻表面,並能 有效加強離子垂直撞擊的效果. 當我們以鎳膜,氧化矽與光阻為光罩材 料蝕刻磷化鎵時,發現鎳膜是最穩定的光罩材料,而光阻因容易受離子撞擊 而變形,導致不佳的蝕刻壁面.氧化矽所得到的效果則介於兩者之間. In this thesis , Reactive Ion Etch of GaP,InGaP,GaN in BCl3/ Ar plasmais studied. The best etching conditions and mask materials are suggested.Higher etch rates and better etched features and sharp side wall profilescan be obtained with higher Ar fraction. Under lower pressure conditions,higher ion density, cleaner etched features and enhanced ion bombardmentin the vertical direction are observed.It is confirmed that etching materials with strong chemical bonds, such as GaN ,requires high ion densityor ion energy. Experiments also show that nickel film is the most stable maskmaterial, compared to SiOx and photoresist.