Scalable biochip and method for making
The present disclosure provides a biochip and methods of fabricating. The biochip includes a fluidic part and a sensing part bonded together using a polymer. The fluidic part has microfluidic channel pattern on one side and fluidic inlet and fluidic outlet on the other side that are fluidly connected to the microfluidic channel pattern. The fluidic inlet and fluidic outlet are formed by laser drilling after protecting the microfluidic channel pattern with a sacrificial protective layer. The polymer bonding is performed at low temperature without damaging patterned surface chemistry on a sensing surface of the sensing part.
1. A method of manufacturing a biochip, comprising:
forming a microfluidic channel pattern on a fluidic substrate;
depositing a sacrificial protective layer over the microfluidic channel pattern;
laser drilling through-holes in the fluidic substrate;
removing the sacrificial protective layer;
providing a sensing wafer having a pattern of modified surface;
forming a polymer pattern on the sensing wafer or on a microfluidic channel pattern side of the fluidic substrate; and
bonding the sensing wafer and the fluidic substrate via the polymer pattern, after forming the microfluidic channel pattern, at a temperature less than about 100 degrees Celsius, the bonding being done in a manner that the microfluidic channel pattern on the fluidic substrate extends away from the through-holes of the fluidic substrate and along an interface of the fluidic substrate and the sensing wafer.
2. The method of claim 1 , wherein the depositing a sacrificial protective layer comprises thermally growing a silicon oxide.
3. The method of claim 1 , wherein the temperature is less than about 60 degrees Celsius.
4. The method of claim 1 , wherein the removing the sacrificial protective layer comprises wet cleaning.
5. The method of claim 1 , wherein the pattern of modified surface includes patterns of bio-functionalization.
6. The method of claim 1 , wherein the polymer is a photoresist.
7. The method of claim 1 , wherein the bonding the sensing wafer and the fluidic substrate comprises treating a surface of the polymer with plasma and alignably contacting the sensing wafer and the fluidic substrate.
8. The method of claim 1 , further comprising dicing the bonded sensing wafer and fluidic substrate into a plurality of biochips wherein the through-holes comprise a fluidic inlet and a fluidic outlet.
9. A method of manufacturing a biochip, comprising:
providing a fluidic substrate having a microfluidic channel pattern on one side, laser drill through-holes, and no post-laser sintering by-products on the microfluidic pattern, the microfluidic channel pattern on the fluidic substrate extending along a surface of the fluidic substrate, away from the laser drill through-holes;
forming a sensing wafer having a plurality of bio-sensors;
depositing a photoresist on a sensing surface side of the sensing wafer;
exposing an exposure portion of the photoresist;
washing a removal portion of the photoresist off the sensing wafer, while leaving a remaining portion of the photoresist on the sensing wafer, to form a first pattern on the sensing surface;
chemically modifying the first pattern;
forming a polymer pattern on the sensing wafer or on a microfluidic channel pattern side of the fluidic substrate; and
bonding the sensing wafer and the fluidic substrate via the polymer pattern.
10. The method of claim 9 , wherein the step of chemically modifying the first pattern comprises bio-functionalizing surfaces of the pattern.
11. The method of claim 10 , further comprising:
depositing a second photoresist on a sensing surface side of the sensing wafer;
exposing an exposure portion of the second photoresist;
washing a removal portion of the second photoresist off the sensing wafer to form a second pattern on the sensing surface; and
bio-functionalizing the second pattern, wherein the first pattern and the second pattern are bio-functionalized differently.
12. The method of claim 9 , wherein the step of chemically modifying the first pattern comprises rendering pattern hydrophobic or hydrophilic.
13. The method of claim 9 , further comprising removing the remaining portion of the photoresist from the sensing wafer.
14. The method of claim 9 , wherein the polymer is polysilesequioxane (PSQ).
15. The method of claim 9 , wherein the polymer pattern is formed on the fluidic substrate by spin-on depositing of a photoresist, exposing the photoresist to the microfluidic channel pattern, removing the photoresist from the microfluidic channels, and baking a remaining portion of the photoresist.
16. The method of claim 15 , wherein the bonding the sensing wafer and the fluidic substrate comprises treating a surface of the polymer on the fluidic substrate with plasma and alignably contacting the sensing wafer and the fluidic substrate, wherein a sensing wafer temperature does not exceed about 60 degrees Celsius during the bonding.
17. A method of manufacturing a biochip, comprising:
forming on a fluidic substrate a microfluidic channel pattern, the microfluidic channel pattern having laser drill through-holes;
removing post-laser sintering by-products on the microfluidic channel pattern;
forming a polymer pattern on a sensing wafer or on a microfluidic channel pattern side of the fluidic substrate, the sensing wafer having a pattern of modified surface; and
bonding the sensing wafer and the fluidic substrate via the polymer pattern after forming the microfluidic channel on the fluidic substrate, the bonding being done in a manner that the microfluidic channel pattern on the fluidic substrate extends away from the through-holes and along an interface of the fluidic substrate and the sensing wafer.
18. The method of claim 17 , wherein the step of removing post-laser sintering by-products on the microfluidic channel pattern comprises;
depositing a sacrificial protective layer over the microfluidic channel pattern before forming the laser drill through-holes; and
removing the sacrificial protective layer after forming the laser drill through-holes.
19. The method of claim 17 , wherein the step of providing a sensing wafer having a pattern of modified surface comprises:
depositing a photoresist on a sensing surface side of the sensing wafer;
exposing an exposure portion of the photoresist;
washing a removal portion of the photoresist off the sensing wafer, while leaving a remaining portion of the photoresist on the sensing wafer, to form a first pattern on the sensing surface; and
chemically modifying the first pattern.
20. The method of claim 17 , wherein the step of bonding the sensing wafer and the fluidic substrate via the polymer comprises bonding at a temperature of less than about 100 degrees Celsius.