BE-GAS REACTION( AND BEF+ IMPLANTS IN GAAS USING IONS PRODUCED FROM SOLID)

Be implantation is widely used for p-type doping in III-V semiconducto rs. Physical sputtering of solid Be may result in some beam instabilit y and low beam current, while solid sources such as BeCl2 require heat ing to achieve high vapor pressure. This work discusses GaAs implantat ion with Be+ and BeF+ ions produced via plasma-etching of solid Be wit h fluorine-containing gases. Etching of Be with BF3 produced Be+ and B eF ions with currents 10 times and 55 times higher than that of Be+ fr om the physical sputtering process, respectively Activation of Be impl anted as Be+ from the new process is comparable to those of the other processes. Activation of Be implanted as BeF+ exhibited higher activat ion energy and lower activation efficiency The BeF+ implant still prov ides reasonable activation f or source/drain and buried layer formatio n under acceptable annealing conditions. The lower effective Be' impla nt energy of the BeF+ implant allows shallow implant depths to be real ized.