Patent ID: 7229502

Claim:
A method of forming a silicon nitride layer suitable for producing micro electro-mechanical (MEM) devices, comprising the steps of: providing a deposition furnace, wherein the deposition furnace comprises: an outer tube; a wafer boat set up inside the outer tube for carrying a plurality of wafers; a gas injector that is positioned between the outer tube and the wafer boat, wherein the gas injector comprises a multi-aperture gas injector that extends vertically in a direction alone the wafer boat; and a uniform gas injection apparatus that is positioned between the outer tube and the wafer boat, wherein the gases injected into the uniform gas injection apparatus are evenly distributed within the deposition furnace; and injecting a silicon-containing gaseous reactant into the deposition furnace via the gas injector and injecting a nitrogen-containing reactant mixed with a carrier gas into the deposition furnace via the uniform gas injection apparatus to form a silicon nitride layer on the wafers, wherein the gas flow rate of the silicon-containing gaseous reactant is greater than the nitrogen-containing gaseous reactant.