LOW-TEMPERATURE DEPOSITION OF SINX-H USING SIH4-N-2 OR SIH4-NH3 DISTRIBUTED ELECTRON-CYCLOTRON-RESONANCE MICROWAVE PLASMA

Silicon nitride films were deposited at floating temperature using dis tributed electron cyclotron resonance plasma enhanced chemical vapor d eposition (DECR-PECVD) on Si and InP substrates. The deposition parame ters studied included the nature of gases (SiH4-N-2 or SiH4-NH3) and t he gas phase composition (SiH4/N-2 or SiH4/NH3). The experimental resu lts establish that to obtain device quality Si3N4, it is desirable to use N-2 instead of NH3 and a high diluted SiH4 gas phase. These proces s parameters yield to a high resistivity (10(16) Omega cm) and a high critical field (4.5 MV/cm). These properties confirm that the DECR tec hnique is well suited for processing III-V compound semiconductors. NH does not induce such promising characteristics in terms of electrical properties but silicon nitride deposited with this gas is particularl y interesting for applications where no stress is required. (C) 1997 A merican Vacuum Society.