The Study of ZnS Thin Films by Atomic Layer Epitaxy

• Main Authors: Nien-chung Lee, 李年中
• Other Authors: Meiso Yokoyama, Y.K.Shu
• Format: Others
• Language: en_US
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/97810032775445755086

碩士 === 國立成功大學 === 電機工程研究所 === 83 === Atomic Layer Epitaxy is a stepwise deposition process by su- pplying the sources materials alternatively.This deposition te- chnique provides monolayer control of the deposited film thick- ness and uniform growth over a large area． ZnS layers were grown epitaxially onto (100)GaAs,(100)Si, (222)ITO substrates under low pressure in a horizontal vaper phase epitaxial reactor using DMZn for the group II source and H2S gas for the group VI source.In this study, We varied the growth condition, including change of the substrate temperature, the mole fraction of DMZn,the mole fraction of H2S,the purge H2 duration, the pressure of reaction chamber ...etc.In order to privide high quality ZnS epitaxial films. In ZnS grown on GaAs,the present process provides the mono- layer growth over a wide range of growth condition in a self- limiting manner.High crystalline quality of the epitaxially grown layers can be obtained by XRD,SEM,EPMA and PL,in spite of very large lattice mismatch (4.4 %) between ZnS and GaAs. In ZnS grown on Si and ITO glasses,The ZnS films have high crystalline quality and the epitaxial layers had a mirror-like surface.But the growth rate was still at 0.7 monolayer over a wise range of growth condition.It may be possible because the adsorption of the reactions on the substrates is weak; and much higher flows or flow times may be needed for monolayer