Biosensing well array with protective layer
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsWei-Cheng Shen, Yi-Hsien Chang, Shih-Wei Lin, Chun-Ren Cheng
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Abstract
The present disclosure provides a biological field effect transistor (BioFET) and a method of fabricating a BioFET device. The method includes forming a BioFET using one or more process steps compatible with or typical to a complementary metal-oxide-semiconductor (CMOS) process. The BioFET includes a microwells having a sensing layer, a top metal stack under the sensing layer, and a multi-layer interconnect (MLI) under the top metal stack. The top metal stack includes a top metal and a protective layer over and peripherally surrounding the top metal.
Claims21
1-10. (canceled)
A method of making a BioFET device, comprising:
- forming a plurality of FETs on a semiconductor substrate, wherein the plurality of FETs each includes a gate structure formed on a first surface of the semiconductor substrate and a channel region;
- forming a gate contact on the gate structure in each of the plurality of FETs;
- forming one or more metal interconnect layers over the plurality of FETs;
- forming a plurality of top metal stacks having a protective layer on sidewalls of the top metal stacks;
- forming a passivation layer over the plurality of top metal stacks;
- etching microwells in the passivation layer to expose a subset of the plurality of top metal stacks, wherein a bottom surface area of the microwells is larger than respective top surfaces of respective ones of the subset of the plurality of top metal stacks;
- depositing a sensing layer in the microwells and over a field portion between the microwells, wherein the sensing layer fills any openings between the subset of the plurality of top metal stacks and the passivation layer;
- and
- removing at least the field portion of the sensing layer.
A method of making a BioFET device, comprising:
- forming on a planar surface of a substrate a top metal layer;
- patterning the top metal layer to form a top metal stack having a top surface and a sidewall;
- forming a protective layer having a protective layer top portion extending along the top surface of the top metal stack and having a protective layer sidewall portion extending along the sidewall of the top metal stack;
- depositing a passivation layer on the protective layer;
- patterning the passivation layer to form an opening, wherein the opening has a bottom formed by the protective layer top portion and the opening has a passivation layer sidewall;
- and
- forming a sensing layer on the protective layer top portion and the protective layer sidewall portion and on the passivation layer sidewall.
A method of making a BioFET device, comprising:
- forming a transistor on a semiconductor substrate;
- forming at least one intermediate metallization layer above and electrically contacting the transistor;
- forming a top metal stack above and electrically contacting the at least one intermediate metallization layer, wherein the top metal stack includes a conductive feature having a top surface and sidewalls;
- forming over the top surface and sidewalls a patterned protective layer;
- and
- forming on the patterned protective layer a sensing layer, wherein the sensing layer extends along the top surface and along the sidewalls.
Dependencies are inferred from the claim text.