Patent ID: 6302962
Filing Date: 2001-10-16
Classification: C30B,H01L

Abstract:
A diffusion system comprising:a furnace having an opening through which a wafer boat is to pass to enter and leave the furnace;a plurality of spray nozzles disposed around said opening of the furnace and collectively operative to form a curtain of gas traversing said opening, said spray nozzles that are disposed around said opening consisting of a first set of spray nozzles confined to one circumferential half of said opening and spaced from one another in the circumferential direction of the opening, and a second set of spray nozzles confined to the other circumferential half of said opening and spaced from one another in the circumferential direction of the opening, said spray nozzles of said first and second sets being oriented to spray gas along respective lines all parallel to one another, and each of the spray nozzles of said first set being offset from each of the spray nozzles of said second set along a direction orthogonal to said parallel lines along which the gas is sprayed by the nozzles such that gas sprayed from the spray nozzles of each one of the sets passes alongside the gas sprayed from the spray nozzles of the other one of the sets while traversing said opening;a source of gas, and a gas supply line connecting said source of gas to said plurality of spray nozzles; anda control unit operative to establish and terminate a flow of gas from said source of gas to said spray nozzles through said gas supply line.