BONDED SILICON STRUCTURE FOR HIGH DENSITY PRINT HEAD

• US 20130120505A1
• Filed: 11/10/2011
• Published: 05/16/2013
• Est. Priority Date: 11/10/2011
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Nystrom, Peter J., Sahu, Bijoyraj
• Granted Patent: US 8,727,508 B2
• Time in Patent Office: Days
• US Class Current: 347/71
• CPC Class Codes: B41J 2/161 of film type, deformed by bending and disposed on a diaphragm
• CPC Class Codes: B41J 2/1629 wet etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2002/14241 having a cover around the piezoelectric thin film element

Abstract

A print head including a jet stack can be formed using semiconductor device manufacturing techniques. A blanket metal layer, a blanket piezoelectric element layer, and a blanket conductive layer can be formed over a semiconductor substrate such as a semiconductor wafer or wafer section. The piezoelectric element layer and the blanket conductive layer can be patterned to provide a plurality of transducer piezoelectric elements and top electrodes respectively, while the metal layer forms a bottom electrode for the plurality of transducers. Subsequently, the semiconductor substrate can be patterned to form a body plate for the print head jet stack. Forming a print head jet stack using semiconductor device manufacturing techniques can provide a high resolution device with small feature sizes.

Claims

1. A method for forming a print head jet stack comprising a plurality of transducers, the method comprising:

forming a metal layer over a semiconductor substrate;

forming a piezoelectric layer over the metal layer;

forming a conductive layer over the piezoelectric layer;

etching the conductive layer to form a plurality of transducer top electrodes for the plurality of transducers;

etching the piezoelectric layer to form a plurality of piezoelectric elements for the plurality of transducers; and

etching the semiconductor substrate to form a body plate from the semiconductor substrate for the print head jet stack.

2. The method of claim 1, further comprising:

forming the metal layer over the semiconductor substrate forms a bottom plate for the plurality of transducers and a diaphragm for the print head jet stack.

3. The method of claim 1, further comprising:

forming an etch stop layer over the semiconductor substrate;

forming the metal layer over the etch stop layer; and

using the etch stop layer as an etch stop during the etching of the semiconductor substrate.

4. The method of claim 1, further comprising:

attaching an inlet/outlet plate to the body plate.

5. The method of claim 1, further comprising:

forming a patterned photoresist layer over the semiconductor substrate; and

performing the etch of the semiconductor substrate using the patterned photoresist layer to pattern the semiconductor substrate to form the body plate for the print head jet stack.

6. The method of claim 5, further comprising:

forming a dielectric interstitial layer over the plurality of transducer top electrodes and between adjacent transducers;

etching the dielectric interstitial layer to expose the plurality of transducer top electrodes;

forming a blanket metal layer over the dielectric interstitial layer to electrically contact the plurality of transducer top electrodes;

forming a patterned mask over the blanket metal layer using lithography; and

etching the blanket metal layer to form a plurality of traces and a plurality of pads electrically coupled to the plurality of transducers, wherein each transducer is individually addressable through the plurality of traces and the plurality of pads.

7. A print head jet stack comprising a plurality of transducers, wherein the print head jet stack comprises:

a semiconductor substrate body plate;

a diaphragm overlying the semiconductor substrate body plate;

a patterned piezoelectric layer overlying the diaphragm; and

a patterned conductive layer overlying the patterned piezoelectric layer,

wherein the diaphragm comprises a conductive bottom electrode of the plurality of transducers, the patterned piezoelectric layer comprises a plurality of piezoelectric elements for the plurality of transducers, and the patterned conductive layer comprises a plurality of top electrodes for the plurality of transducers.

8. The print head jet stack of claim 7, wherein the semiconductor substrate body plate comprises an etched semiconductor wafer section.

9. The print head jet stack of claim 7, wherein the diaphragm is at least one of a chemical vapor deposition (CVD) metal and a sputtered metal.

10. The print head jet stack of claim 7, further comprising:

an etch stop layer interposed between the diaphragm and the semiconductor substrate body plate.

11. The print head jet stack of claim 7, further comprising:

a plurality of conductive pads, with one conductive pad electrically coupled to each transducer of the plurality of transducers; and

a plurality of conductive traces, with one trace electrically coupled to each conductive pad of the plurality of pads,

wherein the plurality of conductive pads and the plurality of conductive traces are each one of a chemical vapor deposition (CVD) metal and a sputtered metal.

12. The print head jet stack of claim 11, further comprising:

an application specific integrated circuit (ASIC) physically attached to the semiconductor substrate and electrically coupled with the plurality of top electrodes for the plurality of transducers.

18. The printer of claim 11, further comprising:

an application specific integrated circuit (ASIC) physically attached to the semiconductor substrate and electrically coupled with the plurality of top electrodes for the plurality of transducers.

13. A printer, comprising:

a print head comprising a print head jet stack, the print head jet stack comprising;

a plurality of transducers;

a semiconductor substrate body plate;

a diaphragm overlying the semiconductor substrate body plate;

a patterned piezoelectric layer overlying the diaphragm; and

a patterned conductive layer overlying the patterned piezoelectric layer,

wherein the diaphragm comprises a conductive bottom electrode of the plurality of transducers, the patterned piezoelectric layer comprises a plurality of piezoelectric elements for the plurality of transducers, and the patterned conductive layer comprises a plurality of top electrodes for the plurality of transducers;

a printer housing which encloses the print head.

14. The printer of claim 13, wherein the semiconductor substrate body plate comprises an etched semiconductor wafer section.

15. The printer of claim 13, wherein the diaphragm is at least one of a chemical vapor deposition (CVD) metal and a sputtered metal.

16. The printer of claim 13, wherein the print head jet stack further comprises:

an etch stop layer interposed between the diaphragm and the semiconductor substrate body plate.

17. The printer of claim 13, wherein the jet stack further comprises:

a plurality of conductive pads, with one conductive pad electrically coupled to each transducer of the plurality of transducers; and

a plurality of conductive traces, with one trace electrically coupled to each conductive pad of the plurality of pads,

wherein the plurality of conductive pads and the plurality of conductive traces are each one of a chemical vapor deposition (CVD) metal and a sputtered metal.