Two-dimensional CVD profile simulator based on ballistic transport and reaction model

Abstract

We have extended the two-dimensional deposition simulator with a micrometer feature scale based on the ballistic transport and reaction model originally developed by Cale et al. (1993) to include a scheme to inhibit and/or accelerate the deposition reaction stemming from the product gases. We have also improved the algorithm used to calculate a self-consistent gas flux distribution on micro features at each step in the simulation. Application of this deposition simulator to seven CVD systems for ULSI usage showed good agreement between the calculated and experimental feature profiles. The validity of the reactive sticking coefficient's role as a general descriptor for step coverage characteristics was thoroughly examined using these simulated results and we concluded that the intrinsic reaction mechanism is more reliable than the sticking coefficient for all CVD characteristics. Molecular orbital calculation was also demonstrated to be extremely helpful in clarifying the intrinsic deposition mechanism.