MANUFACTURE OF SEMICONDUCTOR DEVICE

• Main Author: KOSEKI TAKAYUKI
• Format: Patent
• Language: English
• Published: 12.09.1985
• Edition: 4
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; SEMICONDUCTOR DEVICES

PURPOSE:To contrive the improvement in workability by marked reduction in time required for the process of diffusion before the one-side polishing of a semiconductor substrate by a method wherein impurities of different conductivity type are diffused to both surfaces front and back of the semiconductor substrate of low specific resistance with an impurity of one conductivity type diffused at a high concentration, and thereafter this semiconductor substrate is removed in one side to a thickness of about 1/2. CONSTITUTION:The semiconductor substrate 14 with the specific resistance reduced to a low specific resistance 15 of about 0.02OMEGA.cm or less by diffusion of an N type impurity at a high concentration of 10 cm<-3> is put in a diffusion furnace, and a P type impurity such as boron is diffused from both surfaces front and back to about an approx. 40-50mum depth H1 at a concentration whereby the N type impurity concentration of the low specific resistance layer 15 is dropped to about 10 cm<-9>, resulting in simultaneous formation of high specific resistance layers 16 and 16 of H1 thickness on both surfaces of the layer 15. Next, a semiconductor wafer 17 is obtained by polishing and cutting the substrate 14 from one surface to about 1/2 of its thickness H3.