Method for diffusing as into silicon from a solid phase

Claim 1

The method of claim 1 wherein said glass layer has a thickness in the range of 1000 to 5000 A.

Claim 13

A method for diffusing As into a silicon substrate forming diffused regions having surface impurity concentrations in excess of 1019 atoms/cc comprising, forming a diffusion masking layer on the substrate, forming diffusion windows in said masking layer, forming a thermal silicon oxide layer in the windows having a thickness in the range of 100-900A, forming an As doped layer over at least said diffusion windows, heating the substrate in an inert atmosphere to diffuse As from the doped layer through the silicon oxide layer and into the substrate to the desired depth.

Claim 17

A method for diffusing As into a silicon substrate forming regions having surface impurity concentrations in excess of 1019 atoms/cc comprising, forming on a silicon substrate a composite layer of an upper As doped glassy layer; and an underlying silicate layer having a thickness in the range of 100-900A by separately forming each layer, heating the substrate in an inert gaseous atmosphere selected from the group consisting of N2, Ar, He and mixtures thereof at a temperature in the range of 1,000* to 1,200*C for a time sufficient to cause diffusion of As from the doped glassy layer through the silicate layer and into the silicon substrate to the desired depth.