Granted Patent B2

US 12,569,880 · App. 18/523,949 · Granted Mar 10, 2026

Inventors: Jonathan M. Rothberg (Miami Beach, FL); Keith G. Fife (Palo Alto, CA); Tyler S. Ralston (Clinton, CT); Gregory L. Charvat (Guilford, CT); Nevada J. Sanchez (Guilford, CT)

Assignee: BFLY OPERATIONS, INC.

B06B1/02B06B1/0292B81B3/0021B81B7/0077B81C1/00158G10K9/12G10K11/18B81B2203/0127B81B2203/0315B81B2207/015B81C2201/013B81C2203/0118B81C2203/0735B81C2203/0771

Abstract

Claims (29)

1 . A method for forming a complementary metal oxide semiconductor ultrasonic transducer, the method comprising:

removing a portion of a first layer disposed over a first wafer including an electrode structure and a conductive pillar, wherein the removal of the portion of the first layer exposes a surface of the conductive pillar;

depositing a second layer over the first layer and the exposed surface of the conductive pillar;

forming a cavity in the second layer over the electrode structure, the cavity having a sidewall formed from the second layer; and

bonding a second wafer to the second layer to form a membrane over the cavity, wherein the second wafer and the second layer are doped with the same dopant.

2 . The method according to claim 1 , wherein the first layer is formed from an insulating material.

3 . The method according to claim 1 , wherein the second layer is formed from at least one of silicon, amorphous silicon, or polysilicon.

4 . The method according to claim 1 , wherein at least a portion of the second wafer is formed from at least one of silicon, amorphous silicon, or polysilicon.

5 . The method according to claim 1 , wherein the same dopant is at least one of nitrogen or phosphorus.

6 . The method according to claim 1 , wherein removing the portion of the first layer includes etching.

7 . The method according to claim 1 , wherein the second wafer includes a plurality of layers.

8 . The method according to claim 7 , wherein at least one layer of the plurality of layers of the second wafer and the second layer are doped with the same dopant.

9 . The method according to claim 1 , wherein the first wafer further includes processing circuitry configured to:

actuate the membrane to transmit an ultrasound wave; and

detect a received ultrasound wave based on vibration of the membrane.

10 . A complementary metal oxide semiconductor (CMOS) ultrasonic transducer, comprising:

a first wafer including an electrode structure and a conductive pillar;

a first layer disposed over the first wafer such that a surface of the conductive pillar is exposed through the first layer;

a second layer disposed over the first layer and an exposed surface of the conductive pillar, the second layer having a cavity disposed over the electrode structure, the cavity having a sidewall formed from the second layer; and

a second wafer bonded to the second layer forming a membrane over the cavity, wherein the second wafer and the second layer are doped with the same dopant.

11 . The CMOS ultrasonic transducer according to claim 10 , wherein the first layer is formed from an insulating material.

12 . The CMOS ultrasonic transducer according to claim 10 , wherein the second layer is formed from at least one of silicon, amorphous silicon, or polysilicon.

13 . The CMOS ultrasonic transducer according to claim 10 , wherein at least a portion of the second wafer is formed from at least one of silicon, amorphous silicon, or polysilicon.

14 . The CMOS ultrasonic transducer according to claim 10 , wherein the same dopant is at least one of nitrogen or phosphorus.

15 . The CMOS ultrasonic transducer according to claim 10 , wherein the second wafer includes a plurality of layers.

16 . The CMOS ultrasonic transducer according to claim 15 , wherein at least one layer of the plurality of layers of the second wafer and the second layer are doped with the same dopant.

17 . The CMOS ultrasonic transducer according to claim 10 , wherein the first wafer further includes processing circuitry configured to:

actuate the membrane to transmit an ultrasound wave; and

detect a received ultrasound wave based on vibration of the membrane.

Assignments (2)

Continuity (9)

References Cited (266)