Electrical characteristics of Si devices fabricated with completely consumed carbide (C3) dielectric isolation process

Electrical characteristics of Si devices fabricated with the C3 dielectric isolation process have been investigated. The C3 process produces local field oxide regions due to the differential oxidation rate of SiC versus Si (typically approx. 2-11). Si devices with good electrical properties result when the local oxidation process is allowed to Completely Consume the Carbide (C3) film. This new process is compared to the standard silicon nitride LOCOS process. The bird's beak profiles and the damage on the Si surface resulting from both processes were investigated by SEM and Secco etch, respectively. In order to evaluate the C3 process, MOS capacitors and Schottky barrier diodes have been fabricated with both techniques for varying pad oxide thickness. The measured electrical properties of these devices include lifetime, breakdown voltage, and I-V characteristics. For the minimum bird's beak case (no pad oxide), the C3 process results in superior electrical properties over the standard nitride process.