Systems and methods for anchoring components in MEMS semiconductor devices
View Patent ↗A method of making a semiconductor device forms anchors for one or more layers of material. The method includes depositing a first layer of material on a substrate, applying a mask over the first layer of material to mask nanoparticle-sized areas of the first material, removing portions of the first layer of material to form a first set of recesses around the nanoparticle-sized areas of the first material, depositing a second layer of material in the recesses and over the nanoparticle-sized areas so that a second set of recesses is formed in a top surface of the second layer of material, and forming a component of the semiconductor device over the second layer of material. Material of a bottom surface of the component is included in the second set of recesses.
1. A method of making a semiconductor device, comprising:
depositing a first layer of material on a substrate;
applying a mask over the first layer of material to mask nanoparticle-sized areas of the first material;
removing portions of the first layer of material to form a first set of recesses around the nanoparticle-sized areas of the first material;
depositing a second layer of material in the recesses and over the nanoparticle-sized areas so that a second set of recesses is formed in a top surface of the second layer of material; and
forming a component of the semiconductor device over the second layer of material, wherein material of a bottom surface of the component is included in the second set of recesses.
2. The method of claim 1 , wherein
the mask is applied by depositing nanoclusters on a top surface of the first layer of material, the nanoclusters forming the nanoparticle-sized areas.
3. The method of claim 1 , further comprising:
removing the mask before depositing the second layer of material.
4. The method of claim 1 , wherein the removing portions of the first layer of material includes etching the first layer of material.
5. The method of claim 2 , wherein the second layer of material is deposited over the nanoclusters as well as in the recesses.
6. The method of claim 1 , wherein the semiconductor device is a micro-electrical mechanical sensor (MEMS).
7. The method of claim 6 , wherein the depositing the second layer of material includes conformally depositing the second layer of material, and at least a portion of the first layer of material is an anchor pad for a corresponding portion of the second layer of material.
8. The method of claim 6 , wherein at least a portion of the second layer of material is an anchor pad for the component.
9. The method of claim 2 , wherein
the nanoclusters are one of a group consisting of polysilicon, poly-germanium, and poly-silicon-germanium.
10. The method of claim 1 , wherein
the first layer of material is an oxide.
11. The method of claim 2 , wherein
the second layer of material is polysilicon.
12. A method of making a micro electrical-mechanical sensor (MEMS) device comprising:
depositing a first layer of material on a substrate;
forming a plurality of discontinuous nanoparticles on the first layer of material, wherein the nanoparticles form a mask on a top surface of the first layer;
etching a first set of recesses in areas of the top surface of the first layer that are devoid of the nanoparticles;
depositing a second layer of material over the nanoparticles and in the first set of recesses, a top surface of the second layer of material including a second set of recesses;
forming a component on the second layer of the material, wherein a bottom surface of the component fills at least some recesses of the second set of recesses.
13. The method of claim 12 , further comprising etching the first layer of material until at least some of the recesses in the first set of recesses undercut the nanoparticles.
14. The method of claim 13 , wherein depths of at least some of the first set of recesses range from 200 to 400 Angstroms.