Patent ID: 6695903
Filing Date: 2004-02-24
Classification: C09D,H01L,Y02E,Y10S

Abstract:
A screen-printable dopant paste for the selective patterning and extensive printing of Si wafers to produce p, p+, p++, n, n+, and n++ regions in the Si wafers, said paste comprising:a) one or more components with dopant action, b) one or more silanes of the formula R1nSi(OR)4âˆ’n, in which R1 is methyl, ethyl or phenyl, R is methyl, ethyl, n-propyl or iso-propyl, and n is 0,1 or 2, c) one or more solvents, d) a thickening agent or wetting agent, e) optionally an acid and water, and f) optionally one or more additives, the total composition having impurities in the form of metal ions in respective concentrations of less than 200 ppb, wherein said dopant paste contains 0.1-5% by weight of said silanes.