砷化鎵、磷化銦及磷化銦鎵在三氯化硼、六氟化硫與氬氣中的活性離子蝕刻

Abstract

本論文要旨在研究砷化鎵 ( GaAs )、磷化銦 ( InP ) 及磷化銦鎵 ( InGaP ) 三種化合物半導體在三氯化硼 ( BCl3 )、六氟化硫 ( SF6 )與 氬氣 ( Ar ) 的混合氣體電漿中的活性離子蝕刻 ( Reactive Ion Etching )。所研究的相關變數包括射頻功率密度 ( RF power density )、壓力大小、反應氣體總流量及各氣體流量混合比對蝕刻率 ( etch rate )、蝕刻後材料表面外觀 和自生偏壓 ( self-bias ) 的影響。我 們發現三氯化硼和六氟化硫的流量混合比對蝕刻率有明顯的影響，混合氣 體的蝕刻率遠大於單一氣體的蝕刻率，氬氣的加入則有助於改善被蝕刻表 面的平坦化與側壁的垂直度。本實驗同時應用掃瞄式電子顯微鏡 ( Scanning Electron Microscopy , SEM ) 、 二次離子質譜儀 ( Secondary Ion Mass Spectroscopy , SIMS ) 、 歐傑電子能譜儀 ( Auger Electron Spectroscopy , AES ) 及X射線光電子能譜儀 ( X-ray Photoelectron Spectroscopy , XPS ) 來分析蝕刻後之晶片表面狀況。 In this thesis, the investigation of Reactive Ion Etching ( RIE ) of GaAs, InP and InGaP with BCl3/SF6/Ar mixtures is reported. The etch rate was measured in order to find the dependence on RF power density, pressure, total gas flow rate and the ratio of each gas in the mixtures. The morphology of etched surfaces and self-bias were also in our concern. The ratio of BCl3 and SF6 in gas mixtures has significant influence on etch rate. Etching with both gases is much faster than that with only BCl3 or with only SF6. The addition of Ar may improve the morphology of etched surfaces and sidewalls. Many analytical instruments, such as SEM, SIMS, AES, XPS had been used to analyze morphology and residuals on the etched surfaces.