A process to deposit metal silicon nitride on a substrate comprising: sorbing a metal amide on a heated substrate, purging away the unsorbed metal amide, contacting a silicon-containing source having one or more Si—H3 fragments with the heated substrate to react with the sorbed metal amide, wherein the silicon-containing source has one or more H3Si—NR02(R0═SiH3, R, R1 or R2, defined below) groups selected from the group consisting of one or more of: wherein R and R1 in the formulas represent aliphatic groups typically having from 2 to about 10 carbon atoms, e.g., branched alkyl, cycloalkyl with R and R1 in formula A also being combinable into a cyclic group, and R2 representing a single bond, (CH2)n, a ring, or SiH2, and purging away the unreacted silicon-containing source.