GROWTH OF EPITAXIAL SI1-XGEX LAYERS ON SI(001) SURFACE, BY CATALYTICAL DECOMPOSITION OF DISILANE AND GERMANE - PHOTOEMISSION-STUDIES

Si1-xGex alloys grown by catalytical decomposition of a mixture of dis ilane and germane on Si(001) at 620 K and room temperature (RT) have b een prepared and analyzed in situ with surface techniques such as x-ra y and ultraviolet photoelectron spectroscopies (XPS and UPS), low ener gy electron diffraction (LEED), and x-ray photoelectron diffraction (X PD). A comparison is made with the case of an undecomposed gas mixture under the same experimental conditions. We show that films prepared a t RT are amorphous. Films prepared at 620 K are well ordered and exhib it sharp 2 x 1 LEED patterns. Films grown at RT and subsequently annea led at as high as 820 K have a poorer crystalline quality. (C) 1995 Am erican Institute of Physics.