銻化鋁及砷銻化鋁成長研究

Abstract

本文主要探討以有機金屬氣相磊晶法成長銻化鋁薄膜以及砷銻化鋁薄膜的 固相組成對熱力學因素,長晶速率,長晶溫度和載流氣體流率之間的關係. 實驗結果顯示,在長晶溫度為600度C時,砷銻化鋁薄膜的砷含量和砷的反應 前導物TBAs的通入量之間有正比的關係,和銻的反應前導物TMSb的通入量 幾乎無關.這個結果和熱力學的預測相符合.另外,砷的固相組成會隨長晶 溫度的增加而減少.我們認為這可能和砷及銻的反應前導物的游離反應有 關.而長晶速率和載流氣體流率的增加也會使砷的固相組成減少.當長晶溫 度低於625度C時,長晶速率會隨溫度增加而增加,反應的活化能是16.1 kcal/mole.而對於銻化鋁薄膜的研究中,我們在基板及薄膜之間先長一層 銻化鎵緩衝層,以求改善薄膜的品質.我們觀察在不同的V-III比及長晶溫 度下薄膜品質及長晶速率的變化,加上拉曼光譜的量測結果,以求進一步了 解此材料的特性.實驗結果顯示,在700度C下,銻化鋁的磊晶反應是在動力 限制區,反應的活化能是16.59kcal/mole.我們也發現TMAl和TMSb之間可能 會有催化作用.而拉曼光譜和X-ray繞射儀量測的結果顯示薄膜的品質和長 晶溫度及V-III比有一定的關係. In this study,we have investigated using metalorganic chemical vapor deposition(MOCVD) to grow AlSb and develop the dependence of solid composition of AlAsSbon the factors of themodynamics, growth rate,growth temperature and carrier flow rate.The experiment results indicate that arsenic solid composition of AlAsSb is proportional to molar flow rate of TBAs.This result is agreement with the themodynamic prediction.Otherwise,arsenic solid composition decreased as growthtemperature increased.We think this result might be related to association of TBAs and TMAl.Also,arsenic solid composition decreasedas growth rate and carrier flow rate increased.Growth rate increasedas growth temperature increased when growth temperature is below 625C and the activation energy is 16.1kcal/mole.In the study of AlSb,we first grow a buffer layer between substrate and epilayerin order to improve film quality and investigated variation of growth rate andfilm quality in different V-III ratio and growth temperature.Samples were characterized by means of Ramanspectrum measurement to understand the properties of this material.The experimentresults indicate that when the temperature is below 700C,the growth is kinetically controlled and the activation energy is 16.59kcal/mole.We find that catalysis might exist between TMAl and TMSb.The results of Raman spectrum and X- raydiffraction indicate that film quality is related to growth temperature and V-III ratio.