AVS 49th International Symposium
    Plasma Science Wednesday Sessions
       Session PS+TF-WeP

Paper PS+TF-WeP29
Shallow Trench Isolation Etch for Sub 0.10 µm Applications

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Plasma Etching & Deposition
Presenter: S.M. Williams, Applied Materials
Authors: S.M. Williams, Applied Materials
J. He, Applied Materials
M. Shen, Applied Materials
Correspondent: Click to Email
As feature size continues to shrink to sub 0.10µm and below, photoresist thickness is becoming steadily thinner, and the migration to 193nm resist is beginning. We have developed resist mask and hard mask etch processes, which address the challenges posed by these small feature sizes. Both processes are in situ, with the mask open and trench etch performed in the same chamber, increasing throughput and lowering the cost of ownership. For customers who require near zero nitride loss, the resist mask approach allows the continuation of current integration schemes; by protecting the nitride throughout the trench etch. The process is tunable from 78-88 degrees, and incorporates both top corner and bottom corner rounding in order to minimize leakage current and stress related defects. The resist mask process will eventually run into limitations when resist thicknesses approach 3000Å, especially when 193 nm resist is used, driving STI etch toward the hard mask approach. For customers making a transition from a resist to a hard mask STI etch, it is important to maximize the selectivity to the nitride hard mask in order to minimize the impact on the integration scheme. We have developed a hard mask process, which is highly selective to nitride (>40:1) and tunable from 78-88 degrees. Bottom corner rounding and top corner rounding schemes are incorporated. In addition, the process is HBr free, eliminating the corrosion associated with Br condensation.