Browse Prior Art Database

ISOTROPICALLY ETCHED SILICON NOZZLE FACES

IP.com Disclosure Number: IPCOM000026010D
Original Publication Date: 1989-Oct-31
Included in the Prior Art Database: 2004-Apr-05
Document File: 4 page(s) / 133K

Publishing Venue

Xerox Disclosure Journal

Abstract

It is well known to fabricate ink jet nozzles for silicon printheads using orientation dependent etching (ODE). However, the nature of ODE does not allow a single step process to produce a nozzle face since only interior corners are controllable durin the etching process. If the nozzle face is fabricated by

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 55% of the total text.

Page 1 of 4

EROX DISCLOSURE JOURNAL

ISOTROPICALLY ETCHED SILICON NOZZLE FACES Donald J. Drake

Proposed Classification

U.S. C1.156/626
Int. C1. HOll21/306

FIG. 1

.16

14

FIG. 2

FIG. 3

Volume 14 Number 5 Septernber/October 1989 215

[This page contains 1 picture or other non-text object]

Page 2 of 4

ISOTROPICALLY ETCHED SILICON NOZZLE FACES (Cont'd)

216

12

     XEROX DISCLOSURE JOURNAL Volume 14 Number 5 September/October 1989

FIG. 4

FIG. 5

[This page contains 1 picture or other non-text object]

Page 3 of 4

ISOTROPICALLY ETCHED SILICON NOZZLE FACES (Cont'd)

It is well known to fabricate ink jet nozzles for silicon printheads using orientation dependent etching (ODE). However, the nature of ODE does not allow a single step process to produce a nozzle face since only interior corners are controllable durin the etching process. If the nozzle face is fabricated by

coincident with the (111) crystal plane. For thermal drop on demand applications, it has been found that printheads function better with vertical nozzle faces. This is readily accomplished by dicing, but this procedure has the disadvantage of low throughput, moderate yield, and relatively high expense.

A method of producing etched nozzle faces using an isotropic etch is shown in Figures 1-3. Figure 1 shows, in longitudinal cross section, a channel 10 fabricated in wafer 12 by orientation dependent etching, after patterning vias in silicon nitride layer 14 deposited thereon. The wafer is then recoated with a second silicon nitride layer 16 to protect the channels from etching in subsequent steps.

ODE, it will be slante f relative to the ink channels because the nozzle face is

Figure 2 is a partially shown plan view of Figure 1 showing a via 18 patterned in the two silicon nitride layers. The distance between via 18 and the adjacent ends of channel grooves 10 is about 5 to 10 mils.

In Figure 3, the wafer 12 is shown in cross section after isotropic etching, so that the isotropically etched trough 20 intersects the previously orientation dependent etched channels by predetermined undercutting of the silicon nitride layers. The silicon nitride layer 16 on the exterior of the cha...