WO2005123395A1 - Process for modifying the surface profile of an ink supply channel in a printhead - Google Patents

Process for modifying the surface profile of an ink supply channel in a printhead Download PDF

Info

Publication number
WO2005123395A1
WO2005123395A1 PCT/AU2005/000455 AU2005000455W WO2005123395A1 WO 2005123395 A1 WO2005123395 A1 WO 2005123395A1 AU 2005000455 W AU2005000455 W AU 2005000455W WO 2005123395 A1 WO2005123395 A1 WO 2005123395A1
Authority
WO
WIPO (PCT)
Prior art keywords
ink supply
printhead
etching
wafer
ion milling
Prior art date
Application number
PCT/AU2005/000455
Other languages
French (fr)
Inventor
Darrell Larue Mcreynolds
Kia Silverbrook
Original Assignee
Silverbrook Research Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Silverbrook Research Pty Ltd filed Critical Silverbrook Research Pty Ltd
Priority to AU2005254115A priority Critical patent/AU2005254115B2/en
Priority to EP05714324.0A priority patent/EP1765596B1/en
Priority to CA002567696A priority patent/CA2567696A1/en
Publication of WO2005123395A1 publication Critical patent/WO2005123395A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/16—Production of nozzles
    • B41J2/1621—Manufacturing processes
    • B41J2/1626—Manufacturing processes etching
    • B41J2/1628—Manufacturing processes etching dry etching
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/14—Structure thereof only for on-demand ink jet heads
    • B41J2/14016—Structure of bubble jet print heads
    • B41J2/14088—Structure of heating means
    • B41J2/14112—Resistive element
    • B41J2/1412—Shape
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/16—Production of nozzles
    • B41J2/1601—Production of bubble jet print heads
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/16—Production of nozzles
    • B41J2/1621—Manufacturing processes
    • B41J2/1631—Manufacturing processes photolithography
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/16—Production of nozzles
    • B41J2/1621—Manufacturing processes
    • B41J2/164—Manufacturing processes thin film formation
    • B41J2/1646—Manufacturing processes thin film formation thin film formation by sputtering

Definitions

  • This invention relates to a process for modifying the surface profile of an ink supply channel in a printhead. It has been developed primarily to minimize angular sidewall projections in the ink supply channels, which can disrupt the flow of ink.
  • MEMS Microelectromechanical Systems
  • MEMS Microelectromechanical Systems
  • Photolithographic techniques of course, rely on reliable etching techniques, which allow accurate etching of a silicon substrate revealed beneath a mask.
  • MEMS devices have found applications in a wide variety of fields, such as in physical, chemical and biological sensing devices.
  • One important application of MEMS devices is in inkjet printheads, where micro-scale actuators for inkjet nozzles may be manufactured using MEMS techniques.
  • the present Applicant has developed printheads incorporating MEMS ink ejection devices and these are described in the following patents and patent applications, all of which are incorporated herein by reference.
  • MEMS inkjet printhead (“MEMJET printhead”) is comprised of a plurality of chips, with each chip having several thousand nozzles.
  • Each nozzle comprises an actuator for ejecting ink, which may be, for example, a thermal bend actuator (e.g. US 6,322,195) or a bubble-forming heater element actuator (e.g. US 6,672,709).
  • the chips are manufactured using MEMS techniques, meaning that a high nozzle density and, hence, high resolution printheads can be mass-produced at relatively low cost. In the manufacture of MEMS printhead chips, it is often required to perform deep or ultradeep etches.
  • Etch depths of about 3 ⁇ m to 10 ⁇ m may be termed “deep etches”, whereas etch depths of more than about 10 ⁇ m may be termed “ultradeep etches.
  • MEMS printhead chips typically require delivery of ink to each nozzle through individual ink supply channels having a diameter of about 20 ⁇ m. These ink channels are typically etched through wafers having a thickness of about 200 ⁇ m, and therefore place considerable demands on the etching method employed. It is especially important that each ink channel is perpendicular to the wafer surface and does not contain kinks, sidewall projections (e.g. grassing) or angular junctions, which can interfere with the flow of ink.
  • sidewall projections e.g. grassing
  • FIG. 1 there is shown a typical MEMS nozzle arrangement 1 comprising a bubble-forming heater element actuator assembly 2.
  • the actuator assembly 2 is formed in a nozzle chamber 3 on the passivation layer 4 of a silicon wafer 5.
  • the wafer typically has a thickness "B" of about 200 ⁇ m, whilst the nozzle chamber typically occupies a thickness "A" of about 20 ⁇ m.
  • an ink supply channel 6 is etched through the wafer 5 to the CMOS metallization layers of an interconnect 7.
  • An inlet 8 provides fluid connection between the ink supply channel 6 and the nozzle chamber (removed for clarity in Figure 2).
  • CMOS drive circuitry 9 is provided between the wafer 5 and the interconnect 7.
  • the actuator assembly 2, associated drive circuitry 9 and ink supply channel 6 may be formed on and through a wafer 3 by lithographically masked etching techniques, as described in US application no. 10/302,274, which is incorporated herein by reference.
  • the ink supply channel 6 is formed in the wafer 5 by first etching a trench partially through the wafer 5 from the drop ejection side (i.e.
  • the mask on the ink supply side needs to be carefully aligned so that the etched channels meet the trenches plugged with photoresist, and do not damage the drive circuitry 9.
  • the etching needs to be perpendicular and anisotropic to a depth of about 200 ⁇ m.
  • angular sidewall features in the ink channel, especially at the junction of the ink channel 6 with the inlet 8, are produced. These angular shoulders should ideally be minimized to allow smooth ink flow. Accordingly, there is a demand for improved etching methods, which allow ultradeep trenches having relatively smooth sidewalls to be made in silicon wafers. Several methods for etching ultradeep trenches into silicon are known in the art.
  • DRIE deep reactive ion etching
  • the semiconductor substrate with a suitable mask disposed thereon, is placed on a lower electrode in a plasma reactor, and exposed to an ionized gas plasma formed from a mixture of gases.
  • the ionized plasma gases (usually positively charged) are accelerated towards the substrate by a biasing voltage applied to the electrode.
  • the plasma gases etch the substrate either by physical bombardment, chemical reaction or a combination of both.
  • Etching of silicon is usually ultimately achieved by formation of volatile silicon halides, such as SiF , which are carried away from the etch front by a light inert carrier gas, such as helium.
  • Anisotropic etching is generally achieved by depositing a passivation layer onto the base and sidewalls of the trench as it is being formed, and selectively etching the base of the trench using the gas plasma.
  • One method for achieving ultradeep anisotropic etching is the "Bosch process", described in US 5,501,893 and US 6,284,148. This method involves alternating polymer deposition and etching steps. After formation of a shallow trench, a first polymer deposition step deposits a polymer onto the base and side walls of the trench. The polymer is deposited by a gas plasma formed from a fluorinated gas (e.g. CHF 3 , C 4 F 8 or C1F 4 ) in the presence or in the absence of an inert gas.
  • a fluorinated gas e.g. CHF 3 , C 4 F 8 or C1F 4
  • the plasma gas mix is changed to SF 6 /Ar.
  • the polymer deposited on the base of the trench is quickly broken up by ion assistance in the etching step, while the sidewalls remain protected.
  • anisotropic etching may be achieved.
  • a major disadvantage of the Bosch process is that polymer deposition and etching steps need to be alternated, which means continuously alternating the gas composition of the plasma. This alternation, in turn, leads to uneven trench sidewalls, characterized by scalloped surface formations. At worst, the Bosch process tends to leave grass-like spikes in the sidewalls of the trenches due to incomplete removal of the polymer passivation layer.
  • angular shoulder junctions are a common problem when "back-etching" ink supply channels from the ink supply side of printhead wafers.
  • the present invention provides a process for modifying the surface profile of an ink supply channel in a printhead, said process comprising the steps of: (i) providing a printhead comprising at least one ink supply channel; and (ii) ion milling the at least one ink supply channel.
  • the present invention provides a method of fabricating an inkjet printhead comprising a plurality of nozzles, ejection actuators, associated drive circuitry and ink supply channels, said method comprising the steps of: (i) providing a wafer having a drop ejection side and an ink supply side; (ii) etching a plurality of trenches partially through said drop ejection side of said wafer; (iii) filling said trenches with photoresist; (iv) forming a plurality of corresponding nozzles, ejection actuators and associated drive circuitry on said drop ejection side of said wafer using lithographically masked etching techniques; (v) etching a plurality of corresponding ink supply channels from said ink supply side of said wafer to said photoresist; (vi) modifying the surface profiles of said ink supply channels by ion milling; and (vii) stripping said photoresist from said trenches to form nozzle inlets,
  • the present invention provides an inkjet printhead comprising: a wafer having a drop ejection side and an ink supply side; a plurality of nozzles formed on said drop ejection side, each of said nozzles having a corresponding inlet in said wafer; and a plurality of corresponding ink supply channels leading to each inlet from said ink supply side, wherein shoulders defined by the junction of said ink supply channels with said inlets are tapered and/or rounded. Hitherto, the importance of the surface profile of ink supply channels in printheads fabricated by MEMS techniques had not been fully appreciated.
  • the present invention introduces an additional surface profile modifying step into the printhead manufacturing process, which has the effect of tapering and/or rounding angular surface features in the sidewalls of ink supply channels.
  • printheads made by the process of the present invention generally exhibit improved ink flow through their ink supply channels.
  • angular surface features in the sidewalls of ink supply channels are tapered and/or rounded by the ion milling.
  • An angular surface feature may be, for example, a spike projecting inwardly from a sidewall.
  • the ink supply channel itself is formed by anisotropic ultradeep etching of a semiconductor (e.g. silicon) wafer. Any known anisotropic ultradeep etching technique, such as those described above, may be used to form the ink supply channels.
  • the ion milling is performed in a plasma etching reactor, such as an inductively coupled plasma etching reactor.
  • Plasma etching reactors are well known in the art and are commercially available from various sources (e.g. Surface Technology Systems, PLC).
  • the etching reactor comprises a chamber formed from aluminium, glass or quartz, which contains a pair of parallel electrode plates.
  • a radiofrequency (RF) energy source is used to ionize a plasma gas (or gas mixture) introduced into the chamber. The ionized gas is accelerated towards a substrate disposed on a lower electrode (electrostatic chuck) by a biasing voltage.
  • RF radiofrequency
  • etching is typically achieved purely by physical bombardment of the substrate.
  • Various control means are provided for controlling the biasing voltage, the RF ionizing energy, the substrate temperature, the chamber pressure etc. It will, of course, be within the ambit of the skilled person's common general knowledge to vary plasma reactor parameters in order to optimize etching conditions.
  • the ion milling is performed using a heavy inert gas selected from argon, krypton or xenon.
  • the inert gas is argon since this is widely available at relatively low cost, and, because of its relatively high mass, has excellent sputtering properties.
  • an argon ion plasma is generated in a plasma etching reactor, and the argon ions accelerated perpendicularly towards a silicon wafer having ink supply channels etched therein.
  • the ion milling may be performed at any suitable pressure. Typically, the pressure will be in the range of 5 to 2000 mTorr. In other words, ion milling may be performed at low pressure (about 5 to 250 mTorr) or high pressure (about 250 to 2000 mTorr). Low pressure ion milling has the advantage that most commercially available plasma etching reactors are configured for low pressure etching. Hence, low pressure ion milling does not require any special apparatus. However, ion milling may also be performed at high pressure.
  • High pressure ion milling has the advantage that steeper tapering is usually obtainable.
  • the principle of using a high pressure ion milling to produce steep taper angles may be understood as follows. Normally, sputter etching is performed at relatively low pressures (e.g. about 50 to 250 mTorr) to achieve high sputter etching efficiency. Such a low pressure produces a nearly collision-free path for silicon atoms sputtered from the surface, thereby optimizing etching efficiency. By sputter etching at high pressure rather than low pressure, the mean free path of sputtered silicon atoms is reduced, because sputtered (reflected) silicon atoms have a greater chance of colliding with incoming argon ions in the plasma gas.
  • each ink supply channel has a depth in the range of 100 to 300 ⁇ m, optionally 150 to 250 ⁇ m, or optionally about 200 ⁇ m.
  • each ink supply channel has a diameter in the range of 5 to 30 ⁇ , optionally 14 to 28 ⁇ m, or optionally 17 to 25 ⁇ m.
  • each nozzle inlet has a depth in the range of 5 to 40 ⁇ m, optionally 10 to 30 ⁇ m, or optionally 15 to 25 ⁇ m.
  • each nozzle inlet has a diameter in the range of 3 to 28 ⁇ m, optionally 8 to 24 ⁇ , or optionally 12 to 20 ⁇ m.
  • each ink supply channel has a larger diameter than its corresponding nozzle inlet, and the process of the present invention may be used to taper angular shoulders defined by the junction of the inlet and the channel.
  • Figure 1 shows a perspective view of a prior art printhead nozzle arrangement for a printhead
  • Figure 2 is a cutaway perspective view of the prior art printhead nozzle arrangement shown in Figure 1, with the actuator assembly removed and the ink supply channel exposed
  • Figure 3 is a cutaway perspective view of the printhead nozzle arrangement shown in Figure 2 before stripping away the photoresist plug
  • Figure 4 is a cutaway perspective view of a printhead nozzle arrangement according to the present invention, with the actuator assembly removed and the ink supply channel exposed.
  • FIG. 2 shows a prior art printhead nozzle arrangement having angular shoulders 11, which define a junction between the ink supply channel 6 and the inlet 8. These angular shoulders are formed by prior art ultradeep etching methods described above and in the Applicant's US patent application nos. 10/728,784 (Applicant Ref: MTB08) and 10/728,970 (Applicant Ref: MTB07), both of which are incorporated herein by reference.
  • FIG 3 there is shown an ink supply channel 6 before removal of the photoresist plug 10. The channel 6 is etched partially beyond and around the photoresist plug 10.
  • the wafer is subjected to argon ion milling in a plasma etching reactor.
  • argon ion milling the angular shoulders 11 are tapered by simultaneously etching and redepositing sputtered silicon back onto the sidewalls of the channel.
  • the result is a printhead nozzle arrangement as shown in Figure 4, having tapered shoulders 12, which define the junction between the inlet 8 and the ink supply channel 6.
  • the shoulders may be either fully tapered (as shown in Figure 4) or merely partially rounded.

Landscapes

  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Particle Formation And Scattering Control In Inkjet Printers (AREA)

Abstract

A process for modifying the surface profile of an ink supply channel (6) in a printhead is provided. The process comprises the steps of providing a printhead comprising ink supply channels, and ion milling the ink supply channel (6). The ion milling is generally performed with argon and tends to taper and/or round angular sidewall features (12) in the channel.

Description

PROCESS FOR MODIFYING THE SURFACE PROFILE OF AN INK SUPPLY CHANNEL IN A PRINTHEAD
Field of the Invention This invention relates to a process for modifying the surface profile of an ink supply channel in a printhead. It has been developed primarily to minimize angular sidewall projections in the ink supply channels, which can disrupt the flow of ink.
Cross reference to related application The following patents or patent applications filed by the applicant or assignee of the present invention are hereby incorporated by cross-reference.
6750901 6750901 6476863 6788336 11/003786 11/003354 11/003616
11/003418 11/003334 11/003600 11/003404 11/003419 11/003700 11/003601
11/003618 11/003615 11/003337 11/003698 11/003420 11/003682 11/003699
CAA018US 11/003463 11/003701 11/003683 11/003614 11/003702 11/003684
11/003619 11/003617 6623101 6406129 6505916 6457809 6550895
6457812 IJ52NPUS 6428133 10/815625 10/815624 10/815628 10/913375
10/913373 10/913374 10/913372 10/913377 10/913378 10/913380 10/913379
10/913376 10/913381 10/986402 10/407212 10/760272 10/760273 10/760187
10/760182 10/760188 10/760218 10/760217 10/760216 10/760233 10/760246
10/760212 10/760243 10/760201 10/760185 10/760253 10/760255 10/760209
10/760208 10/760194 10/760238 10/760234 10/760235 10/760183 10/760189
10/760262 10/760232 10/760231 10/760200 10/760190 10/760191 10/760227
10/760207 10/760181 10/728804 10/728952 10/728806 10/728834 10/729790
10/728884 10/728970 10/728784 10/728783 10/728925 10/728842 10/728803
10/728780 10/728779 10/773189 10/773204 10/773198 10/773199 6830318
10/773201 10/773191 10/773183 10/773195 10/773196 10/773186 10/773200
10/773185 10/773192 10/773197 10/773203 10/773187 10/773202 10/773188
10/773194 10/773193 10/773184 11/008118 MTB38US MTB39US 10/727181
10/727162 10/727163 10/727245 10/727204 10/727233 10/727280 10/727157
10/727178 10/727210 10/727257 10/727238 10/727251 10/727159 10/727180
10/727179 10/727192 10/727274 10/727164 10/727161 10/727198 10/727158
10/754536 10/754938 10/727227 10/727160 10/934720 PEC01NPUS 6795215
10/296535 09/575109 6805419 6859289 09/607985 6398332 6394573
6622923 6747760 10/189459 10/884881 10/943941 10/949294 10/039866
10/854521 10/854522 10/854488 10/854487 10/854503 10/854504 10/854509 10/854510 10/854496 10/854497 10/854495 10/854498 10/854511 10/854512
10/854525 10/854526 10/854516 10/854508 10/854507 10/854515 10/854506
10/854505 10/854493 10/854494 10/854489 10/854490 10/854492 10/854491
10/854528 10/854523 10/854527 10/854524 10/854520 10/854514 10/854519
PLT036US 10/854499 10/854501 10/854500 10/854502 10/854518 10/854517
10/934628 10/760254 10/760210 10/760202 10/760197 10/760198 10/760249
10/760263 10/760196 10/760247 10/760223 10/760264 10/760244 10/760245
10/760222 10/760248 10/760236 10/760192 10/760203 10/760204 10/760205
10/760206 10/760267 10/760270 10/760259 10/760271 10/760275 10/760274
10/760268 10/760184 10/760195 10/760186 10/760261 10/760258 11/014764
RRB002US 11/014748 11/014747 11/014761 11/014760 11/014757 11/014714
11/014713 RRB010US 11/014724 11/014723 11/014756 11/014736 11/014759
11/014758 11/014725 11/014739 11/014738 11/014737 11/014726 11/014745
11/014712 11/014715 11/014751 11/014735 11/014734 RRB030US 11/014750
11/014749 11/014746 11/014769 11/014729 11/014743 11/014733 RRC005US
11/014755 11/014765 11/014766 11/014740 11/014720 RRC011US 11/014752
11/014744 11/014741 11/014768 RRC016US 11/014718 11/014717 11/014716
11/014732 11/014742 09/575197 09/575197 09/575195 09/575159 09/575132
09/575130 09/575165 6813039 09/575118 09/575131 09/575116 6816274
09/575139 09/575186 6681045 6728000 09/575145 09/575192 09/575181
09/575193 09/575183 6789194 09/575150 6789191 6644642 6502614
6622999 6669385 6549935 09/575187 6727996 6591884 6439706
6760119 09/575198 6290349 6428155 6785016 09/575174 6822639
6737591 09/575154 09/575129 6830196 6832717 09/575189 09/575170
09/575171 09/575161 09/575123 6825945
Some applications have been listed by docket numbers. These will be replaced when application numbers are known.
Background of the Invention The impact of MEMS (Microelectromechanical Systems) devices on the microelectronics industry has been extremely significant in recent years. Indeed, MEMS is one of the fastest growing areas of microelectronics. The growth of MEMS has been enabled, to a large extent, by the extension of silicon-based photolithography to the manufacture of micro-scale mechanical devices and structures. Photolithographic techniques, of course, rely on reliable etching techniques, which allow accurate etching of a silicon substrate revealed beneath a mask. MEMS devices have found applications in a wide variety of fields, such as in physical, chemical and biological sensing devices. One important application of MEMS devices is in inkjet printheads, where micro-scale actuators for inkjet nozzles may be manufactured using MEMS techniques. The present Applicant has developed printheads incorporating MEMS ink ejection devices and these are described in the following patents and patent applications, all of which are incorporated herein by reference.
6,227,652 6,213,588 6,213,589 6,231,163 6,247,795 6,394,581 6,244,691 6,257,704 6,416,168 6,220,694 6,257,705 6,247,794 6,234,610 6,247,793 6,264,306 6,241,342 6,247,792 6,264,307 6,254,220 6,234,611 6,302,528 6,283,582 6,239,821 6,338,547 6,247,796 6,557,977 6,390,603 6,362,843 6,293,653 6,312,107 6,227,653 6,234,609 6,238,040 6,188,415 6,227,654 6,209,989 6,247,791 6,336,710 6,217,153 6,416,167 6,243,113 6,283,581 6,247,790 6,260,953 6,267,469 6,273,544 6,309,048 20,196 6,443,558 6,439,689 6,378,989 6,848,181 6,634,735 6,623,101 6,406,129 6,505,916 6,457,809 6,550,895 6,457,812 6,428,133 6,362,868 6,755,509
Typically a MEMS inkjet printhead ("MEMJET printhead") is comprised of a plurality of chips, with each chip having several thousand nozzles. Each nozzle comprises an actuator for ejecting ink, which may be, for example, a thermal bend actuator (e.g. US 6,322,195) or a bubble-forming heater element actuator (e.g. US 6,672,709). The chips are manufactured using MEMS techniques, meaning that a high nozzle density and, hence, high resolution printheads can be mass-produced at relatively low cost. In the manufacture of MEMS printhead chips, it is often required to perform deep or ultradeep etches. Etch depths of about 3 μm to 10 μm may be termed "deep etches", whereas etch depths of more than about 10 μm may be termed "ultradeep etches. MEMS printhead chips typically require delivery of ink to each nozzle through individual ink supply channels having a diameter of about 20 μm. These ink channels are typically etched through wafers having a thickness of about 200 μm, and therefore place considerable demands on the etching method employed. It is especially important that each ink channel is perpendicular to the wafer surface and does not contain kinks, sidewall projections (e.g. grassing) or angular junctions, which can interfere with the flow of ink. In the Applicant's US patent application nos. 10/728,784 (Applicant Ref: MTB08) and 10/728,970 (Applicant Ref: MTB07), both of which are incorporated herein by reference, there is described a method of fabricating inkjet printheads from a wafer having a drop ejection side and an ink supply side. Referring to Figure 1, there is shown a typical MEMS nozzle arrangement 1 comprising a bubble-forming heater element actuator assembly 2. The actuator assembly 2 is formed in a nozzle chamber 3 on the passivation layer 4 of a silicon wafer 5. The wafer typically has a thickness "B" of about 200 μm, whilst the nozzle chamber typically occupies a thickness "A" of about 20 μm. Referring to Figure 2, an ink supply channel 6 is etched through the wafer 5 to the CMOS metallization layers of an interconnect 7. An inlet 8 provides fluid connection between the ink supply channel 6 and the nozzle chamber (removed for clarity in Figure 2). CMOS drive circuitry 9 is provided between the wafer 5 and the interconnect 7. The actuator assembly 2, associated drive circuitry 9 and ink supply channel 6 may be formed on and through a wafer 3 by lithographically masked etching techniques, as described in US application no. 10/302,274, which is incorporated herein by reference. Referring to Figure 3, the ink supply channel 6 is formed in the wafer 5 by first etching a trench partially through the wafer 5 from the drop ejection side (i.e. nozzle side) of the wafer. (This trench will become the inlet 8, shown in Figure 2). Once formed, the trench is plugged with photoresist 10, as shown in Figure 3, and the ink supply channel 6, is formed by ultradeep etching from the ink supply side of the wafer 5 to the photresist plug 10. Finally, the photoresist 10 is stripped from the trench to form the inlet 8, which provides fluid connection between the ink supply channel 6 and the nozzle chamber 3. This "back-etching" technique avoids filling and removing an entire 200 μm long ink supply channel with resist whilst nozzle structures in the wafer are being lithographically formed. However, there are a number of problems associated with back-etching the ink supply channels in this way. Firstly, the mask on the ink supply side needs to be carefully aligned so that the etched channels meet the trenches plugged with photoresist, and do not damage the drive circuitry 9. Secondly, the etching needs to be perpendicular and anisotropic to a depth of about 200 μm. Thirdly, angular sidewall features in the ink channel, especially at the junction of the ink channel 6 with the inlet 8, are produced. These angular shoulders should ideally be minimized to allow smooth ink flow. Accordingly, there is a demand for improved etching methods, which allow ultradeep trenches having relatively smooth sidewalls to be made in silicon wafers. Several methods for etching ultradeep trenches into silicon are known in the art. All these methods involve deep reactive ion etching (DRIE) using a gas plasma. The semiconductor substrate, with a suitable mask disposed thereon, is placed on a lower electrode in a plasma reactor, and exposed to an ionized gas plasma formed from a mixture of gases. The ionized plasma gases (usually positively charged) are accelerated towards the substrate by a biasing voltage applied to the electrode. The plasma gases etch the substrate either by physical bombardment, chemical reaction or a combination of both. Etching of silicon is usually ultimately achieved by formation of volatile silicon halides, such as SiF , which are carried away from the etch front by a light inert carrier gas, such as helium. Anisotropic etching is generally achieved by depositing a passivation layer onto the base and sidewalls of the trench as it is being formed, and selectively etching the base of the trench using the gas plasma. One method for achieving ultradeep anisotropic etching is the "Bosch process", described in US 5,501,893 and US 6,284,148. This method involves alternating polymer deposition and etching steps. After formation of a shallow trench, a first polymer deposition step deposits a polymer onto the base and side walls of the trench. The polymer is deposited by a gas plasma formed from a fluorinated gas (e.g. CHF3, C4F8 or C1F4) in the presence or in the absence of an inert gas. In the subsequent etching step, the plasma gas mix is changed to SF6/Ar. The polymer deposited on the base of the trench is quickly broken up by ion assistance in the etching step, while the sidewalls remain protected. Hence, anisotropic etching may be achieved. However, a major disadvantage of the Bosch process is that polymer deposition and etching steps need to be alternated, which means continuously alternating the gas composition of the plasma. This alternation, in turn, leads to uneven trench sidewalls, characterized by scalloped surface formations. At worst, the Bosch process tends to leave grass-like spikes in the sidewalls of the trenches due to incomplete removal of the polymer passivation layer. These grass-like residues are especially undesirable in ink supply channels, because ink flow through the channels may break off the grassy spikes and block the ink nozzles downstream. Furthermore, shaφ sidewall projections create air pockets in the ink, which can lead to poor ink flow and, hence, poor print quality and/or nozzle blocking. A modification of the cyclical Bosch process is described in US 6,127,278, assigned to Applied Materials, Inc. In the Applied Materials process, a first passivation etch is performed using a HBr/θ2 plasma, followed by a main etch using a SF6/HBr/θ2 in alternating succession. The HBr enhances passivation, probably by formation of relatively nonvolatile silicon bromides in the passivation layer. However, this cyclical passivation/etching process still suffers from grassing and scalloped sidewalls, which are evident in the Bosch process. Another ultradeep anisotropic etching process is the "Lam process", described in US 6,191,043. The Lam process utilizes a constant, non-alternating plasma gas chemistry of SF6/02/Ar/He and achieves simultaneous sidewall passivation during the etch. To some extent, this avoids the problems of scalloped sidewalls and grassing resulting from cyclical etching processes. However, there is still a need to improve the surface profiles of ultradeep trenches in order to minimize the deleterious effects of grassing and scalloped sidewalls. It would be especially desirable to minimize angular junctions between nozzle inlets and ink supply channels in printheads. As discussed above, angular shoulder junctions are a common problem when "back-etching" ink supply channels from the ink supply side of printhead wafers.
Summary of the Invention In a first aspect, the present invention provides a process for modifying the surface profile of an ink supply channel in a printhead, said process comprising the steps of: (i) providing a printhead comprising at least one ink supply channel; and (ii) ion milling the at least one ink supply channel. In a second aspect, the present invention provides a method of fabricating an inkjet printhead comprising a plurality of nozzles, ejection actuators, associated drive circuitry and ink supply channels, said method comprising the steps of: (i) providing a wafer having a drop ejection side and an ink supply side; (ii) etching a plurality of trenches partially through said drop ejection side of said wafer; (iii) filling said trenches with photoresist; (iv) forming a plurality of corresponding nozzles, ejection actuators and associated drive circuitry on said drop ejection side of said wafer using lithographically masked etching techniques; (v) etching a plurality of corresponding ink supply channels from said ink supply side of said wafer to said photoresist; (vi) modifying the surface profiles of said ink supply channels by ion milling; and (vii) stripping said photoresist from said trenches to form nozzle inlets, thereby providing fluid connection between said ink supply side and said nozzles. In a third aspect, the present invention provides an inkjet printhead comprising: a wafer having a drop ejection side and an ink supply side; a plurality of nozzles formed on said drop ejection side, each of said nozzles having a corresponding inlet in said wafer; and a plurality of corresponding ink supply channels leading to each inlet from said ink supply side, wherein shoulders defined by the junction of said ink supply channels with said inlets are tapered and/or rounded. Hitherto, the importance of the surface profile of ink supply channels in printheads fabricated by MEMS techniques had not been fully appreciated. Whilst several ultradeep etching techniques have become available in recent years, none of these addresses the problems of grassing, scalloped sidewalls and/or angular shoulder junctions between nozzle inlets and ink supply channels. The present invention introduces an additional surface profile modifying step into the printhead manufacturing process, which has the effect of tapering and/or rounding angular surface features in the sidewalls of ink supply channels. Hence, printheads made by the process of the present invention generally exhibit improved ink flow through their ink supply channels. Optionally, angular surface features in the sidewalls of ink supply channels are tapered and/or rounded by the ion milling. An angular surface feature may be, for example, a spike projecting inwardly from a sidewall. Alternatively, it may be an angled shoulder at the point where the ink supply channel narrows into a nozzle inlet. The process of the present invention advantageously tapers these angular surface features, such that they are generally rounded or smoothed off. Hence, ink flowing past these features approaches a curved surface rather than an angular surface. This means that the ink can flow smoothly past, without generating excessive turbulence and/or air bubbles in pockets behind jutting projections where ink is flowing relatively slowly. Typically, the ink supply channel itself is formed by anisotropic ultradeep etching of a semiconductor (e.g. silicon) wafer. Any known anisotropic ultradeep etching technique, such as those described above, may be used to form the ink supply channels. Optionally, the ion milling is performed in a plasma etching reactor, such as an inductively coupled plasma etching reactor. Plasma etching reactors are well known in the art and are commercially available from various sources (e.g. Surface Technology Systems, PLC). Typically, the etching reactor comprises a chamber formed from aluminium, glass or quartz, which contains a pair of parallel electrode plates. However, other designs of reactor are available and the present invention is suitable for use with any type of plasma etching reactor. A radiofrequency (RF) energy source is used to ionize a plasma gas (or gas mixture) introduced into the chamber. The ionized gas is accelerated towards a substrate disposed on a lower electrode (electrostatic chuck) by a biasing voltage. In the present invention, etching is typically achieved purely by physical bombardment of the substrate. Various control means are provided for controlling the biasing voltage, the RF ionizing energy, the substrate temperature, the chamber pressure etc. It will, of course, be within the ambit of the skilled person's common general knowledge to vary plasma reactor parameters in order to optimize etching conditions. Optionally, the ion milling is performed using a heavy inert gas selected from argon, krypton or xenon. Preferably, the inert gas is argon since this is widely available at relatively low cost, and, because of its relatively high mass, has excellent sputtering properties. Typically, an argon ion plasma is generated in a plasma etching reactor, and the argon ions accelerated perpendicularly towards a silicon wafer having ink supply channels etched therein. The ion milling may be performed at any suitable pressure. Typically, the pressure will be in the range of 5 to 2000 mTorr. In other words, ion milling may be performed at low pressure (about 5 to 250 mTorr) or high pressure (about 250 to 2000 mTorr). Low pressure ion milling has the advantage that most commercially available plasma etching reactors are configured for low pressure etching. Hence, low pressure ion milling does not require any special apparatus. However, ion milling may also be performed at high pressure. High pressure ion milling has the advantage that steeper tapering is usually obtainable. The principle of using a high pressure ion milling to produce steep taper angles may be understood as follows. Normally, sputter etching is performed at relatively low pressures (e.g. about 50 to 250 mTorr) to achieve high sputter etching efficiency. Such a low pressure produces a nearly collision-free path for silicon atoms sputtered from the surface, thereby optimizing etching efficiency. By sputter etching at high pressure rather than low pressure, the mean free path of sputtered silicon atoms is reduced, because sputtered (reflected) silicon atoms have a greater chance of colliding with incoming argon ions in the plasma gas. The result is that a gaseous cloud is formed above the substrate surface, which redeposits reflected silicon atoms back onto the silicon surface. There is an increasing net deposition of reflected silicon atoms at greater depths, which results in angular surface features in the sidewalls becoming more tapered. US 5,888,901, which is incorporated herein by reference, describes high pressure ion milling of a SK , dielectric surface using argon as the sputtering gas. Whilst the method described in US 5,888,901 is used for tapering a Si02 dielectric surface layer, rather than tapering angular surface features on the sidewalls of ultradeep channels etched into silicon, this method may be readily modified and applied to the process of the present invention. Low pressure ion milling is generally preferred in the present invention, because it is usually only necessary to round off angular sidewall features in order to achieve improved ink flow, rather than taper the whole sidewall feature. Moreover, low pressure ion milling does not require any special apparatus and can therefore be easily incorporated into a typical printhead fabrication process. Optionally, each ink supply channel has a depth in the range of 100 to 300 μm, optionally 150 to 250 μm, or optionally about 200 μm. Optionally, each ink supply channel has a diameter in the range of 5 to 30 μ , optionally 14 to 28 μm, or optionally 17 to 25 μm. Optionally, each nozzle inlet has a depth in the range of 5 to 40 μm, optionally 10 to 30 μm, or optionally 15 to 25 μm. Optionally, each nozzle inlet has a diameter in the range of 3 to 28 μm, optionally 8 to 24 μ , or optionally 12 to 20 μm. Usually, each ink supply channel has a larger diameter than its corresponding nozzle inlet, and the process of the present invention may be used to taper angular shoulders defined by the junction of the inlet and the channel.
Brief Description of the Drawings Figure 1 shows a perspective view of a prior art printhead nozzle arrangement for a printhead; Figure 2 is a cutaway perspective view of the prior art printhead nozzle arrangement shown in Figure 1, with the actuator assembly removed and the ink supply channel exposed; Figure 3 is a cutaway perspective view of the printhead nozzle arrangement shown in Figure 2 before stripping away the photoresist plug; and Figure 4 is a cutaway perspective view of a printhead nozzle arrangement according to the present invention, with the actuator assembly removed and the ink supply channel exposed.
Detailed Description of a Preferred Embodiment Figure 2 shows a prior art printhead nozzle arrangement having angular shoulders 11, which define a junction between the ink supply channel 6 and the inlet 8. These angular shoulders are formed by prior art ultradeep etching methods described above and in the Applicant's US patent application nos. 10/728,784 (Applicant Ref: MTB08) and 10/728,970 (Applicant Ref: MTB07), both of which are incorporated herein by reference. Referring to Figure 3, there is shown an ink supply channel 6 before removal of the photoresist plug 10. The channel 6 is etched partially beyond and around the photoresist plug 10. In accordance with the present invention, at this stage of printhead fabrication, the wafer is subjected to argon ion milling in a plasma etching reactor. Optimal operating parameters of the plasma etching reactor may be readily determined by the person skilled in the art. During the argon ion milling, the angular shoulders 11 are tapered by simultaneously etching and redepositing sputtered silicon back onto the sidewalls of the channel. The result is a printhead nozzle arrangement as shown in Figure 4, having tapered shoulders 12, which define the junction between the inlet 8 and the ink supply channel 6. Depending on the pressure, the bias power and or the milling time, the shoulders may be either fully tapered (as shown in Figure 4) or merely partially rounded. In either case, the removal of sharply angled shoulders 11 generally improves ink flow through the channel 6 and minimizes pockets of turbulence and/or air bubble formation. It will, of course, be appreciated that the present invention has been described purely by way of example and that modifications of detail may be made within the scope of the invention, which is defined by the accompanying claims.

Claims

1. A process for modifying the surface profile of at least one ink supply channel in a printhead, said process comprising the steps of: (i) providing a printhead comprising at least one ink supply channel; and (ii) ion milling said at least one ink supply channel.
2. The process of claim 1, wherein said printhead comprises a plurality of ink supply channels.
3. The process of claim 1 , wherein angular surface features in the sidewalls of said at least one channel are tapered and/or rounded by said ion milling.
4. The process of claim 1, wherein said ion milling is performed in a plasma etching reactor.
5. The process of claim 1 , wherein said ion milling is performed with an inert gas selected from the group consisting of argon, krypton and xenon.
6. The process of claim 1, wherein said ion milling is performed at a pressure in the range of 5 to 2000 mTorr.
7. The process of claim 1, wherein said ink supply channel has a depth in the range of 100 to 300 μm.
8. The process of claim 1, wherein said ink supply channel has a diameter in the range of 2 to 30 μm.
9. A printhead comprising a plurality of ink supply channels, wherein said ink supply channels are modified by a process according to claim 1.
10. A method of fabricating an inkjet printhead comprising a plurality of nozzles, ejection actuators, associated drive circuitry and ink supply channels, said method comprising the steps of: (i) providing a wafer having a drop ejection side and an ink supply side; (ii) etching a plurality of trenches partially through said drop ejection side of said wafer; (iii) filling said trenches with photoresist; (iv) forming a plurality of corresponding nozzles, ejection actuators and associated drive circuitry on said drop ejection side of said wafer using lithographically masked etching techniques; (v) etching a plurality of corresponding ink supply channels from said ink supply side of said wafer to said photoresist; (vi) modifying the surface profiles of said ink supply channels by ion milling; and (vii) stripping said photoresist from said trenches to form nozzle inlets, thereby providing fluid connection between said ink supply side and said nozzles.
11. The method of claim 10, wherein shoulders defined by the junction of said ink supply channels with said inlets are tapered and/or rounded by said ion milling.
12. The method of claim 10, wherein said trenches have a depth in the range of 5 to 150 μm.
13. The method of claim 10, wherein said ink supply channels and/or said trenches are etched by an anisotropic deep reactive ion etching process.
14. A printhead fabricated by a method according to claim 10.
15. An inkjet printhead comprising: a wafer having a drop ejection side and an ink supply side; a plurality of nozzles formed on said drop ejection side, each of said nozzles having a corresponding inlet in said wafer; and a plurality of corresponding ink supply channels leading to each inlet from said ink supply side, wherein shoulders defined by the junction of said ink supply channels with said inlets are tapered and/or rounded.
16. The inkjet printhead of claim 15, wherein each ink supply channel has a larger diameter than its corresponding inlet, and each channel tapers inwardly towards its corresponding inlet.
17. The inkjet printhead of claim 15, wherein each ink supply channel has a depth in the range of 100 to 300 μm.
18. The inkjet printhead of claim 15, wherein each ink supply channel has a diameter in the range of 5 to 30 μm.
19. The inkjet printhead of claim 15, wherein each inlet has a depth in the range of 5 to 40 μm.
20. The inkjet printhead of claim 15, wherein each inlet has a diameter in the range of 3 to 28 μm.
PCT/AU2005/000455 2004-06-17 2005-03-31 Process for modifying the surface profile of an ink supply channel in a printhead WO2005123395A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
AU2005254115A AU2005254115B2 (en) 2004-06-17 2005-03-31 Process for modifying the surface profile of an ink supply channel in a printhead
EP05714324.0A EP1765596B1 (en) 2004-06-17 2005-03-31 Process for modifying the surface profile of an ink supply channel in a printhead
CA002567696A CA2567696A1 (en) 2004-06-17 2005-03-31 Process for modifying the surface profile of an ink supply channel in a printhead

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10/868,866 US20050280674A1 (en) 2004-06-17 2004-06-17 Process for modifying the surface profile of an ink supply channel in a printhead
US10/868,866 2004-06-17

Publications (1)

Publication Number Publication Date
WO2005123395A1 true WO2005123395A1 (en) 2005-12-29

Family

ID=35480122

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AU2005/000455 WO2005123395A1 (en) 2004-06-17 2005-03-31 Process for modifying the surface profile of an ink supply channel in a printhead

Country Status (6)

Country Link
US (1) US20050280674A1 (en)
EP (1) EP1765596B1 (en)
CN (1) CN100586723C (en)
AU (1) AU2005254115B2 (en)
CA (1) CA2567696A1 (en)
WO (1) WO2005123395A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100857629B1 (en) 2004-10-08 2008-09-08 실버브룩 리서치 피티와이 리미티드 Method of removing polymer coating from an etched trench
US7481943B2 (en) * 2005-08-08 2009-01-27 Silverbrook Research Pty Ltd Method suitable for etching hydrophillic trenches in a substrate
US7437820B2 (en) * 2006-05-11 2008-10-21 Eastman Kodak Company Method of manufacturing a charge plate and orifice plate for continuous ink jet printers
US7855151B2 (en) * 2007-08-21 2010-12-21 Hewlett-Packard Development Company, L.P. Formation of a slot in a silicon substrate
JP6333055B2 (en) * 2014-05-13 2018-05-30 キヤノン株式会社 Substrate processing method and liquid discharge head substrate manufacturing method
US10391771B2 (en) 2015-10-30 2019-08-27 Hewlett-Packard Development Company, L.P. Print bar

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0609012A2 (en) 1993-01-25 1994-08-03 Hewlett-Packard Company Method for manufacturing a thermal ink-jet print head
US6127278A (en) 1997-06-02 2000-10-03 Applied Materials, Inc. Etch process for forming high aspect ratio trenched in silicon
US6191043B1 (en) 1999-04-20 2001-02-20 Lam Research Corporation Mechanism for etching a silicon layer in a plasma processing chamber to form deep openings
US20010024219A1 (en) * 2000-03-21 2001-09-27 Nec Corporation Nozzle plate structure for ink-jet printing head and method of manufacturing nozzle plate
EP0786345B1 (en) * 1996-01-26 2002-11-20 Seiko Epson Corporation Ink jet recording head and manufacturing method therefor
US20030085960A1 (en) 2001-11-02 2003-05-08 Samsung Electronics Co., Ltd Monolithic ink-jet printhead and method of manufacturing the same
US6672713B2 (en) * 1999-12-24 2004-01-06 Fujitsu Limited Ink-jet recording head and method of producing the same
EP1422063A1 (en) 2002-11-21 2004-05-26 Samsung Electronics Co., Ltd. Monolithic ink-jet printhead having heater disposed between dual ink chambers and manufacturing method thereof

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5279669A (en) * 1991-12-13 1994-01-18 International Business Machines Corporation Plasma reactor for processing substrates comprising means for inducing electron cyclotron resonance (ECR) and ion cyclotron resonance (ICR) conditions
US5278584A (en) * 1992-04-02 1994-01-11 Hewlett-Packard Company Ink delivery system for an inkjet printhead
US5883650A (en) * 1995-12-06 1999-03-16 Hewlett-Packard Company Thin-film printhead device for an ink-jet printer
US6305790B1 (en) * 1996-02-07 2001-10-23 Hewlett-Packard Company Fully integrated thermal inkjet printhead having multiple ink feed holes per nozzle
US5744400A (en) * 1996-05-06 1998-04-28 Accord Semiconductor Equipment Group Apparatus and method for dry milling of non-planar features on a semiconductor surface
WO1999065689A1 (en) * 1998-06-18 1999-12-23 Matsushita Electric Industrial Co., Ltd. Fluid jetting device and its production process
US6473966B1 (en) * 1999-02-01 2002-11-05 Casio Computer Co., Ltd. Method of manufacturing ink-jet printer head
EP1070589A3 (en) * 1999-07-19 2001-07-18 Nec Corporation Ink-jet recording head, method for fabricating same and method for ejecting ink droplets
US6502918B1 (en) * 2001-08-29 2003-01-07 Hewlett-Packard Company Feature in firing chamber of fluid ejection device
US6767474B2 (en) * 2002-07-19 2004-07-27 Hewlett-Packard Development Company, L.P. Fluid ejector head having a planar passivation layer
US20050130075A1 (en) * 2003-12-12 2005-06-16 Mohammed Shaarawi Method for making fluid emitter orifice

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0609012A2 (en) 1993-01-25 1994-08-03 Hewlett-Packard Company Method for manufacturing a thermal ink-jet print head
EP0609012B1 (en) * 1993-01-25 1997-05-28 Hewlett-Packard Company Method for manufacturing a thermal ink-jet print head
EP0786345B1 (en) * 1996-01-26 2002-11-20 Seiko Epson Corporation Ink jet recording head and manufacturing method therefor
US6127278A (en) 1997-06-02 2000-10-03 Applied Materials, Inc. Etch process for forming high aspect ratio trenched in silicon
US6191043B1 (en) 1999-04-20 2001-02-20 Lam Research Corporation Mechanism for etching a silicon layer in a plasma processing chamber to form deep openings
US6672713B2 (en) * 1999-12-24 2004-01-06 Fujitsu Limited Ink-jet recording head and method of producing the same
US20010024219A1 (en) * 2000-03-21 2001-09-27 Nec Corporation Nozzle plate structure for ink-jet printing head and method of manufacturing nozzle plate
US20030085960A1 (en) 2001-11-02 2003-05-08 Samsung Electronics Co., Ltd Monolithic ink-jet printhead and method of manufacturing the same
EP1422063A1 (en) 2002-11-21 2004-05-26 Samsung Electronics Co., Ltd. Monolithic ink-jet printhead having heater disposed between dual ink chambers and manufacturing method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP1765596A4 *

Also Published As

Publication number Publication date
AU2005254115B2 (en) 2008-08-07
EP1765596A1 (en) 2007-03-28
CA2567696A1 (en) 2005-12-29
CN100586723C (en) 2010-02-03
EP1765596B1 (en) 2013-07-17
CN1968819A (en) 2007-05-23
EP1765596A4 (en) 2008-02-20
AU2005254115A1 (en) 2005-12-29
US20050280674A1 (en) 2005-12-22

Similar Documents

Publication Publication Date Title
US7837887B2 (en) Method of forming an ink supply channel
US6555480B2 (en) Substrate with fluidic channel and method of manufacturing
EP1011028B1 (en) A method for fabrication of multi-step structures using embedded etch stop layers
US8608288B2 (en) Liquid drop ejector having self-aligned hole
AU2005254115B2 (en) Process for modifying the surface profile of an ink supply channel in a printhead
Akashi et al. Deep reactive ion etching of borosilicate glass using an anodically bonded silicon wafer as an etching mask
US7524430B2 (en) Fluid ejection device structures and methods therefor
US7481943B2 (en) Method suitable for etching hydrophillic trenches in a substrate
US7202178B2 (en) Micro-fluid ejection head containing reentrant fluid feed slots
US20140306301A1 (en) Silicon substrate mems device
US8877605B1 (en) Silicon substrate fabrication
JP2012200799A (en) Method of manufacturing silicon structure
US7413915B2 (en) Micro-fluid ejection head containing reentrant fluid feed slots
Akashi et al. Deep reactive ion etching of pyrex glass using a bonded silicon wafer as an etching mask

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWE Wipo information: entry into national phase

Ref document number: 2567696

Country of ref document: CA

WWE Wipo information: entry into national phase

Ref document number: 2005254115

Country of ref document: AU

WWE Wipo information: entry into national phase

Ref document number: 200580019635.5

Country of ref document: CN

NENP Non-entry into the national phase

Ref country code: DE

WWW Wipo information: withdrawn in national office

Country of ref document: DE

WWE Wipo information: entry into national phase

Ref document number: 2005714324

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2005254115

Country of ref document: AU

Date of ref document: 20050331

Kind code of ref document: A

WWP Wipo information: published in national office

Ref document number: 2005714324

Country of ref document: EP