核心層光電子激發術對化學氣相沉積磊晶法在Si(100)表面成長磷薄膜的研究

Abstract

類磊晶成長n-type的Si半導體時,PH3 常被作為參雜的雜質,因此瞭解PH3 與Si表面的基本反應過程是非常重要的.本論文利用核心層光電子激發術 以化學氣相沉積磊晶法在Si(100)表面上吸附PH3的現象>研究結果顯示PH3 熱反應的產物隨不同的加熱溫度而改變.在低溫的範圍(300K-620K),PH3熱 反應的產物為PH3,PH2與H.而在更高溫時(650K-720k)時,PH3熱反應的產物 為P-P雙原子團,PH2以及h.當加熱溫度大於770K,H原子完全離開Si表面,且 表面原子排列為P-Si混成雙原子團及P-P雙原子團.溫度為300K時,PH3吸附 表面之後,PH3分解與否主要受 到曝氣時的流量與表面P原子覆蓋率的影 響.在吸附溫度為850K時,表面P原子的覆蓋率達到最大值,此時,表面上有 P-P雙原子團形成. Phosphine is a molecule widely used in chemical vapor deposition (CVD)procession for n0type doping of silicon. So it is important to understand growth kinetics. The interaction of phosphine with the Si(100) surface in CVD processes has been investigated with core-level photoemission spectroscopy.the adsorption and thermal decomposition of phosphine depends strongly onsubstrate temperature. When a surface saturated with phosphine is annealedto the low annealing temperature regime(300-620K), the thermal dissociation fragments are attributed primarily to PH2 + H. At higher annealing annealingtemperature(650-720K), the surface contains Si-P heterodimers,PH2 and H. Athigh annealing temperature (>770K), the surface hydrogen desorb completely here, the surface P atoms from P-P dimer. At 300K, phosphine is found to adsorb bothdissociativitely and nondissociatively, depending on the phosphine flux and phosphorus coverage. during exposure.At maximun phosphorus coverage, pbtained by adsorption at 850K,P-P dimers are found.