AR-IMPLANTATION OF CU AND AG FROM THE SI(111)-QUASI-5X5-CU AND CU( ION RECOIL)SI(111)-ROOT-3X-ROOT-3-AG SURFACES IN THE KEV REGIME/

The concentration changes of Cu and Ag at the Cu/Si(111)root 3 x root 3-Ag and Si(111)-quasi-5 x 5-Cu surfaces by 5 keV Ar+ ion bombardment have been measured by means of AES and RES techniques in order to dete rmine the cross sections or their recoil-implantation and desorption. From the obtained cross section for recoil-implantation we have evalua ted the potential barrier height for recoil-implantation, It is also f ound that the Si(111)-quasi-5 x 5-Cu structure is easily destroyed by Ar+ ion bombardment. From the results for the Cu/Si(111)-root 3 x root 3-Ag surface, together with the observed root 3 x root 3 LEED pattern , we propose a hypothesis that Ag atoms are accommodated at the top-mo st surface and that Cu atoms are buried at an interstitial sire in the Si substrate.