Method of depositing heater material over a photoresist scaffold

• US 7,468,139 B2
• Filed: 02/18/2005
• Issued: 12/23/2008
• Est. Priority Date: 07/15/1997
• Status: Expired due to Fees

• Current Assignee: Memjet Technology Ltd. (Memjet Limited)
• Original Assignee: Silverbrook Research Pty Limited
• Inventors: Silverbrook, Kia
• Primary Examiner(s): Ahmed; Shamim
• Application Number:
  US11/060,805
• Publication Number:
  US 20050162475A1
• Time in Patent Office: 1,404 Days
• Field of Search: 216/27, 216/41, 216/58, 216/83, 298/901, 347/54, 347/65
• US Class Current: 216/27
• CPC Class Codes: B41J 2/1412 Shape
• CPC Class Codes: B41J 2/14427 Structure of ink jet print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/1601 Production of bubble jet print heads B41J2/1606, B41J2/162 take precedence
• CPC Class Codes: B41J 2/1623 bonding and adhesion
• CPC Class Codes: B41J 2/1626 etching
• CPC Class Codes: B41J 2/1628 dry etching
• CPC Class Codes: B41J 2/1629 wet etching
• CPC Class Codes: B41J 2/1631 photolithography
• CPC Class Codes: B41J 2/1632 machining
• CPC Class Codes: B41J 2/1635 dividing the wafer into individual chips
• CPC Class Codes: B41J 2/1637 molding
• CPC Class Codes: B41J 2/1639 sacrificial molding
• CPC Class Codes: B41J 2/1642 thin film formation by CVD [chemical vapor deposition]
• CPC Class Codes: B41J 2/1643 thin film formation by plating
• CPC Class Codes: B41J 2/1645 thin film formation by spincoating
• CPC Class Codes: B41J 2/1646 thin film formation by sputtering
• CPC Class Codes: B41J 2/1648 Production of print heads with thermal bend detached actuators
• CPC Class Codes: B41J 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/17503 Ink cartridges
• CPC Class Codes: B41J 2/17513 Inner structure
• CPC Class Codes: B41J 2/17596 : Ink pumps, ink valves
• CPC Class Codes: B41J 2002/041 : Electromagnetic transducer
• CPC Class Codes: B41J 2002/14346 : Ejection by pressure produced by thermal deformation of ink chamber, e.g. buckling
• CPC Class Codes: B41J 2002/14435 : Moving nozzle made of thermal bend detached actuator
• CPC Class Codes: B41J 2202/21 : Line printing
• CPC Class Codes: B82Y 30/00 : Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: G06F 1/1626 : with a single-body enclosure integrating a flat display, e.g. Personal Digital Assistants [PDAs]
• CPC Class Codes: G06F 21/79 : in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 21/86 : Secure or tamper-resistant housings
• CPC Class Codes: G06F 2221/2129 : Authenticate client device independently of the user
• CPC Class Codes: G06K 1/121 : by printing code marks applying code marks to labels B65C9/46; marking or coding completed packages B65B61/26
• CPC Class Codes: G06K 19/06037 : multi-dimensional coding
• CPC Class Codes: G06K 7/14 : using light without selection of wavelength, e.g. sensing reflected white light G06K7/10831 - G06K7/1097 take precedence
• CPC Class Codes: G06K 7/1417 : 2D bar codes
• CPC Class Codes: G11C 11/56 : using storage elements with more than two stable states represented by steps, e.g. of voltage, current, phase, frequency
• CPC Class Codes: H04N 1/2154 : the still video camera incorporating a hardcopy reproducing device, e.g. a printer
• CPC Class Codes: H04N 2101/00 : Still video cameras
• CPC Class Codes: H04N 23/00 : Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 5/2628 : Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation
• CPC Class Codes: Y10T 29/49401 : Fluid pattern dispersing device making, e.g., ink jet

Abstract

A method of forming a nozzle for an inkjet printhead is provided. The nozzle comprises a suspended heater element, which is formed by depositing heater material over a sacrificial photoresist scaffold, the scaffold having sloped side faces. The sloped side faces improve deposition of the heater material between the heater element and adjacent electrodes.

Claims

1. A method of forming an inkjet printhead with a suspended heater element, the method comprising at least the steps of:

depositing a layer of photoresist on a substrate;

masking the layer of photoresist with a mask that is opaque to light of a predetermined wavelength;

focusing a source of light at the predetermined wavelength on to the mask and the layer of photoresist to cure portions of the layer of photoresist;

etching away uncured photoresist from the layer of photo resist to form a sacrificial photoresist scaffold having sloped side faces; and

,

depositing heater material over the sacrificial photoresist scaffold;

wherein,

the sloped side faces are formed using a predetermined focusing condition employed by the source of light during exposure of the layer of photoresist.

2. The method of claim 1, wherein the inkjet printhead has a nozzle corresponding to the suspended heater, the nozzle being supported on a front face of the substrate.

3. The method of claim 2, wherein the sacrificial photoresist scaffold has a substantially planar upper surface.

4. The method of claim 3, wherein the upper surface is substantially parallel with the front face of the substrate.

5. The method of claim 1, wherein the sacrificial photoresist scaffold is substantially disc-shaped.

6. The method of claim 2, wherein the sacrificial photoresist scaffold is formed, at least partially, over a nozzle inlet plugged with photoresist.

7. The method of claim 1, wherein at least two electrodes are positioned adjacent the heater element, the electrodes being provided for passing an actuating current through the heater element.

8. The method of claim 7, wherein the heater material is deposited over the electrodes at the same time as being deposited over the sacrificial photoresist scaffold.

9. The method of claim 8, wherein the sloped side faces provide increased deposition of heater material between the heater element and the electrodes.

10. The method of claim 1, wherein the heater material is comprised of TiAlN.

11. The method of claim 1, wherein the heater element comprises the heater material sandwiched between a lower and an upper passivation films.

12. The method of claim 11, wherein the passivation films are comprised of a material selected from the group consisting of tantalum, tantalum nitride and silicon nitride.

13. The method of claim 11, wherein the lower passivation film is deposited onto the sacrificial photoresist scaffold prior to deposition of the heater material.

14. The method of claim 2, wherein the sloped faces are angled at between 45 and 85°

relative to the front face of the substrate.

15. The method of claim 1, further comprising the steps of:

forming a nozzle chamber for the suspended heater element; and

removing the sacrificial photoresist scaffold.

16. A method of fabricating an inkjet printhead comprising a plurality of suspended heater elements, each suspended heater element being formed by a method according to claim 1.