Method of making BIOMEMS devices
View Patent ↗A MEMS device is manufactured by first forming a self-aligned monolayer (SAM) on a carrier wafer. Next, a first polymer layer is formed on the self-aligned monolayer. The first polymer layer is patterned form a microchannel cover, which is then bonded to a patterned second polymer layer on a device wafer to form microchannels. The carrier wafer is then released from the first polymer layer.
1. A method of making a MEMS device comprising:
forming a self-aligned monolayer (SAM) on a carrier wafer;
forming a first polymer layer on said self-assembled monolayer;
patterning said first polymer layer to form a microchannel cover;
bonding said microchannel cover to a patterned second polymer layer on a device wafer to form microchannels;
releasing said carrier wafer from the first polymer layer, and
wherein said second polymer layer comprises first and second sublayers of polymer, said first sublayer is deposited first, said second sublayer is subsequently deposited on said first sublayer, and said second sublayer is then patterned to form sidewalls of the microchannels on the device wafer.
2. A method as claimed in claim 1 , wherein the self-aligned monolayer is subjected to post-deposition treatment to perform cross-linking.
3. A method as claimed in claim 2 , wherein the self-aligned monolayer is (Tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane, C 8 H 4 Cl 3 F 13 Si.
4. A method as claimed in claim 2 , wherein the self-aligned monolayer is selected from the group consisting of dimethyldichlorosilane, tridecafluoro-1, and heptadecafluoro-1,1,2,2-tetrahydrodecyltrichlorosilane.
5. A method as claimed in claim 2 , wherein said first polymer layer is a photopolymer which is selectively exposed to radiation through a mask to define the microchannel cover.
6. A method as claimed in claim 5 , wherein said photopolymer is a negative tone photopolymer.
7. A method as claimed in claim 1 , wherein said first photopolymer layer is applied by spinning directly onto the self-aligned monolayer.
8. A method as claimed in claim 7 , wherein said first polymer layer is about 20 μm thick.
9. A method as claimed in claim 5 , wherein said first photopolymer layer is subjected to a pre-exposure bake not exceeding 95° C.
10. A method as claimed in claim 1 , wherein each said sublayer comprises a negative tone photopolymer.
11. A method as claimed in claim 1 , wherein said second sublayer is a photopolymer, and said second sublayer is exposed through a mask to form said sidewalls.
12. A method as claimed in claim 11 , wherein after developing the second sublayer, said second sublayer is subjected to a vacuum bake at about 180° C.
13. A method as claimed in claim 1 , wherein the carrier wafer and device wafer are bonded together by pressing them together into intimate contact at a temperature of 120-150° C. in a vacuum.
14. A method as claimed in claim 1 , wherein the device wafer contains multiple CMOS drivers.