Influence of boron ion implantation on the mechanics and electret properties of Si/sub 3/N/sub 4/ single layer film

Amorphous silicon nitride (Si/sub 3/N/sub 4/) film has outstanding electret properties and it is compatible with micromachining technology. Therefore, it is expected to be used as an electret vibrating membrane in miniature microphones. One of the most important parameters of characterizing electret-vibrating membranes is flexibility. So the reduction of internal stress due to boron ion implantation for the LPCVD Si/sub 3/N/sub 4/ film on silicon substrate is discussed first. The charge storage ability for the Si/sub 3/N/sub 4/ films B+ implanted by various doses and energies are investigated by means of negative corona charging, the isothermal surface potential decay measurements and open-circuit thermally stimulated discharge (TSD) current spectrum analysis.