A METHOD OF MAKING P-DOPED SILICON FILMS

摘要

The production of improved photovoltaic solar cells and the like comprising both p and n type deposited silicon film regions is made possible by a process which provides more efficient p-doped silicon films with higher acceptor concentrations. The process utilizes previously known p-dopant metal or boron gaseous materials in unique forms and conditions in a glow discharge silicon preferably hydrogen and fluorine compensated deposition process. Thus, p-dopant metals like aluminum may be used in an elemental evaporated form, rather than in a gaseous compound form heretofore ineffectively used and deposited with the glow discharge deposited silicon on substrates kept at lower temperatures where fluorine and hydrogen compensation is most effective. Preferably boron in a gaseous compound form like diborane and other p-dopant metals in a gaseous form are used uniquely during the glow discharge deposition of silicon by heating the substrate to heretofore believed undesirably higher temperatures, like at least about 450 DEG C. to 800 DEG C. where at least fluorine compensation, if desired, is still effective. The improved devices, such as solar cells, can be manufactured in a continuous process on a web type substrate moved through a plurality of film deposition chambers. Each of the chambers is dedicated to depositing a particular type of film layer (p, i or n) and is isolated from the other chambers.