Dry etching of Combined Gallium Nitride Epitaxial Layer and Silicon Carbide Substrate

Background
The contract is issued for the purpose of dry etching combined Gallium Nitride epitaxial layers and Silicon Carbide substrates. The goal is to fabricate high-quality wafers that meet specific technical requirements, which are essential for advanced semiconductor applications.

Work Details
The vendor shall perform the following tasks:

1. Fabricate one 3” and approximately 350 microns thick single crystal 4H-SiC wafer, which is already electroplated with a patterned nickel etch mask.

2. Etch the wafer to 280 microns to create a diaphragm with an approximate thickness of 70 microns, with diaphragm radii ranging from 300 microns to 900 microns.

3. Use reasonable effort to achieve a smooth diaphragm with fewer than 5 micro mask artifacts on each etched diaphragm surface.

4. Ensure diaphragm thickness uniformity across the 3” wafer of ±5% of the target thickness of 70 microns.

5. Achieve diaphragm features that are smooth and free of scallops.

6. Maintain a reasonable radius at the intersection of the diaphragm base with the sidewall without notching.

7. Ensure that edge-wall trenching artifacts at the intersection of the diaphragm base and sidewall are not present.

8. Maintain an aspect ratio (etched depth/etched width) of no less than 5, with a preference for higher ratios.

9. The etch recipe will be determined by the foundry.

10. Dry-etch the top side p-GaN to a depth of 3 μm using an SiO etch mask to expose the underlying 4H-SiC surface, confirming that the etched depth is indeed 3 microns.

Bidder Requirements
No explicit bidder requirements such as set-aside status, security clearances, or professional certifications are mentioned in the solicitation.