METHOD FOR CREATING DEVICE

• US 20160187299A1
• Filed: 12/22/2015
• Published: 06/30/2016
• Est. Priority Date: 12/25/2014
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Wang, Shinan, Setomoto, Yutaka
• Granted Patent: US 10,338,034 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B06B 1/0292 Electrostatic transducers, e.g. electret-type
• CPC Class Codes: B06B 1/0644 using a single piezoelectric element B06B1/0688 takes precedence
• CPC Class Codes: B81B 2201/0271 Resonators; ultrasonic resonators
• CPC Class Codes: B81B 2207/07 Interconnects
• CPC Class Codes: B81B 3/0086 Electrical characteristics, e.g. reducing driving voltage, improving resistance to peak voltage
• CPC Class Codes: B81C 1/00158 Diaphragms, membranes manufacture process for semi-permeable inorganic membranes B01D67/0039
• CPC Class Codes: G01N 29/2406 Electrostatic or capacitive probes, e.g. electret or cMUT-probes
• CPC Class Codes: G01N 29/2418 using optoacoustic interaction with the material, e.g. laser radiation, photoacoustics photoacoustic cells G01N21/1702; measuring characteristics of vibrations by using radiation-sensitive means G01H9/00; acousto-optical conversion techniques for short-range imaging G01S15/8965; sound-producing devices using laser bundle G10K15/046
• CPC Class Codes: G01N 29/2437 Piezoelectric probes

Abstract

A method for creating an electronic device including a semiconductor substrate, an element unit, a through wiring line, and a wiring portion includes forming interstitial via holes in a first surface of the substrate, forming a first insulating film on the inner walls of the via holes, forming openings that reach the first insulating film on the bottoms of the via holes from a second surface of the substrate, forming a second insulating film on the bottoms of the openings, forming a through wiring line in the via holes, forming an element unit that electrically connects the through wiring line, reducing the thickness of the substrate from the second surface so that the second surface becomes flush with the second insulating film on the bottoms of the openings, and forming a wiring portion, on the second insulating film, that electrically connects to the through wiring line.

Claims

1. A method for creating a device comprising an element portion including electrodes, a substrate including a first surface and a second surface opposite to the first surface, and a through wiring line extending from the first surface to the second surface, the electrodes being electrically connected to the through wiring line, the method comprising the steps of:

forming first holes from the first surface of the substrate, the first holes having a depth with which the first holes does not pass through the substrate;

forming a first insulating film on inner walls of the first holes;

forming second holes that reach the first insulating film from the second surface of the substrate opposite to the first insulating film;

forming a second insulating film on the second holes;

injecting a material of the through wiring line into the first holes;

forming the element portion on the first surface, the element portion electrically connecting to the material of the through wiring line;

thinning the substrate from the second surface of the substrate to the second insulating film; and

forming a wiring portion on the second insulating film, the wiring portion connecting to the material of the through wiring line.

2. The method for creating the device according to claim 1, wherein the steps are performed in the order according to claim 1.

3. The method for creating the device according to claim 1, wherein the substrate comprises a semiconductor substrate.

4. The method for creating the device according to claim 3, wherein the semiconductor substrate comprises a silicon substrate.

5. The method for creating the device according to claim 4, wherein the first insulating film is a silicon thermal oxide film.

6. The method for creating the device according to claim 4, wherein the second insulating film comprises a silicon thermal oxide film.

7. The method for creating the device according to claim 1, wherein the first holes have a depth of 300 μ

m or less.

8. The method for creating the device according to claim 1, wherein the substrate reduced in thickness has a thickness of 300 μ

m or less.

9. The method for creating the device according to claim 1, wherein the element portion comprises a capacitive micro-machined ultrasonic transducer including a cell including a first electrode, a second electrode disposed across a void from the first electrode, and a diaphragm formed of insulating films disposed above and under the second electrode, the diaphragm being supported so as to vibrate.

10. The method for creating the device according to claim 1, wherein the element portion comprises a piezoelectric transducer including a first electrode and a second electrode disposed across a piezoelectric material from the first electrode.

11. The method for creating the device according to claim 1, wherein the step of thinning the substrate is executed in a state in which a support substrate is bonded to the first surface of the substrate before the thinning step.

12. The method for creating the device according to claim 1, wherein the step of injecting the material of the through wiring line comprises injecting the material of the through wiring line into the first holes using electrolytic plating.

13. The method for creating the device according to claim 1, wherein the step of forming the wiring portion comprises forming openings in the first insulating film and the second insulating film and forming the wiring portion electrically connecting to the material of the through wiring line via the openings.

14. A device comprising:

a semiconductor substrate including a first surface and a second surface opposite to the first surface, the substrate having a thickness of 300 μ

m or less;

a through wiring line passing through the substrate between the first surface and the second surface;

electrodes electrically connected to the through wiring line; and

an insulating film between the through wiring line and the semiconductor substrate, the insulating film being a silicon thermal oxide film formed by thermal oxidation at a temperature of 800°

C. or higher, a silicon nitride film formed by CVD at a temperature of 800°

C. or higher, or two or more layers of the silicon thermal oxide film or the silicon nitride film.

15. The device according to claim 14, wherein the device comprises a capacitive micro-machined ultrasonic transducer.

16. The device according to claim 14, wherein the device comprises a piezoelectric transducer.

17. A subject-information acquisition apparatus comprising:

the transducer according to claim 15; and

a processing unit configured to acquire information on

a subject using an electrical signal output from the transducer,

wherein the transducer receives acoustic waves from the subject and converts the acoustic waves to the electrical signal.

18. The subject-information acquisition apparatus according to claim 17, further comprising:

a light source,

wherein the transducer receives photoacoustic waves generated from the subject irradiated with light emitted from the light source and converts the photoacoustic waves to an electrical signal, and

wherein the processing unit acquires information on the subject using the electrical signal.

19. A subject-information acquisition apparatus comprising:

the transducer according to claim 16; and

a processing unit configured to acquire information on a subject using an electrical signal output from the transducer,

wherein the transducer receives acoustic waves from the subject and converts the acoustic waves to the electrical signal.

20. The subject-information acquisition apparatus according to claim 19, further comprising:

a light source,

wherein the transducer receives photoacoustic waves generated from the subject irradiated with light emitted from the light source and converts the photoacoustic waves to an electrical signal, and

wherein the processing unit acquires information on the subject using the electrical signal.

21. A subject-information acquisition apparatus comprising:

the transducer according to claim 15;

a light source; and

a processing unit configured to acquire information of a subject using an electrical signal output from the transducer,

wherein the transducer receives acoustic waves generated from the subject irradiated with light emitted from the light source and converts the acoustic waves to the electrical signal.

22. A subject-information acquisition apparatus comprising:

a transducer according to claim 16;

a light source; and

a processing unit configured to acquire information a subject using an electrical signal output from the transducer,

wherein the transducer receives acoustic waves generated from the subject irradiated with light emitted from the light source and converts the acoustic waves to the electrical signal.

23. A measuring apparatus comprising:

the transducer configured to receive external force according to claim 15,

wherein the measuring apparatus measures a magnitude of the external force applied to a surface of the transducer using an electrical signal from the transducer.

24. A measuring apparatus comprising:

the transducer configured to receive external force according to claim 16,

wherein the measuring apparatus measures a magnitude of the external force applied to a surface of the transducer using an electrical signal from the transducer.