Micromachined structures made by combined wet and dry etching
View Patent ↗A micromachined structure, comprising: a substarte; a first wet etched pit disposed in the substrate; a second wet etched pit disposed in the substrate, the second pit extending into the substrate a greater depth than the first pit; and a dry pit disposed between, and adjacent to, the first and second pits. Also disclosed is a micromachined substrate comprising: a wet etched pit; and a dry-etched hole disposed in the wet etched pit, wherein the dry hole extends through the substrate.
1. A micromachined structure, comprising:
a substrate;
a first wet-etched pit disposed in the substrate;
a second wet-etched pit disposed in the substrate, the second wet-etched pit extending into the substrate a greater depth than the first wet-etched pit and comprising a flat surface parallel to the upper surface of the substrate; and
a dry-etched pit disposed between, and adjacent to, the first and second wet-etched pits.
2. The micromachined structure of claim 1 , wherein the substrate comprises < 100 > silicon.
3. The micromachined structure of claim 1 , wherein the first wet-etched pit comprises a flat surface parallel to the upper surface of the substrate.
4. The micromachined structure of claim 3 , comprising at least one of a VCSEL or a photodetector mounted to the flat surface of the second wet-etched pit.
5. A micromachined structure comprising:
a substrate;
a first wet-etched pit disposed in the substrate;
a second wet-etched pit disposed in the substrate, the second wet-etched pit extending into the substrate a greater depth than the first wet-etched pit; and
a dry-etched pit disposed between, and adjacent to, the first and second wet-etched pits;
wherein the dry-etched pit is disposed within the second wet-etched pit and wherein the dry-etched pit circumscribes the first wet-etched pit.
6. The micromachined structure of claim 1 , wherein the first wet-etched comprises a V-shaped cross-section.
7. A micromachined structure comprising:
a substrate;
a first wet-etched pit disposed in the substrate;
a second wet-etched pit disposed in the substrate, the second wet-etched pit extending into the substrate a greater depth than the first wet-etched pit; and
a dry-etched pit disposed between, and adjacent to, the first and second wet-etched pits;
wherein the first wet-etched pit comprises a V-shaped cross-section and the second wet-etched pit comprises a pyramidal pit.
8. The micromachined substrate of claim 7 , comprising a ball lens disposed in the second wet-etched pit and an optical fiber disposed in the first wet-etched pit.
9. The micromachined structure of claim 1 , wherein the dry-etched pit is a linear trench.