以有機金屬氣相磊晶法成長銻化銦/砷化鎵薄膜

Abstract

本文主要探討以有機金屬氣相磊晶法(MOCVD)在砷化鎵(GaAs)基板上成長 銻化銦(InSb)薄膜 ，希望藉由銻化銦/砷化鎵的異質磊晶研究，充份了 解磊晶參數對成長銻化銦薄膜的影響。 這些參數包括磊晶溫度、反應物 分子源 V/III 比值、以及載流氫氣流量。實驗結果顯示， 在未刻意攙雜 雜質的情況下，所成長的銻化銦薄膜均呈 N-type。當磊晶溫度在 440℃ ~470 ℃時，銻化銦薄膜的磊晶成長主要由表面動力主導。磊晶溫度固定 在 460℃時，長晶速率約為 1.8 □m/hr 幾乎與 V/III 比值的變化 1.0~3.5 無關。由各種量測結果顯示，本實驗室所成長的最佳銻化銦薄膜 ，磊晶溫度為 460℃、V/III 比值為 2.5。此試片之雙晶X-ray 的半高寬 值為 590 arcsec、拉曼光譜中 TO/LO 比值約為 0.45、室溫載子遷移率 可達 18,600 cm2/V-s。 Metalorganic chemical vapor epitaxial growth of InSb on (100)GaAs substrate has been performed using trimethylindium (TMIn) and trimethylantimony (TMSb) as source precursors. These experiments were conducted in a growth temperature range from 440讈 to 470讈 and an input V/III gas ratio from 1.0 to 3.5. Experimental results show that the growth rate for InSb is surface-kinetic controlled in the above growth temperature region. The associated growth rate (~1.8 熤/hr @T=460讈) does not depend on the TMSb/TMIn ratio from 1.0 to 3.5. The optimum InSb film quality obtained in our system was carried out at 460讈 and V/III= 2.5. The resulted film has an x-ray rocking curve of 590 arcsec and a Hall mobility of 18,600 cm2/V-s at 300K.