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Title: Submicron patterned metal hole etching

Abstract

A wet chemical process for etching submicron patterned holes in thin metal layers using electrochemical etching with the aid of a wetting agent. In this process, the processed wafer to be etched is immersed in a wetting agent, such as methanol, for a few seconds prior to inserting the processed wafer into an electrochemical etching setup, with the wafer maintained horizontal during transfer to maintain a film of methanol covering the patterned areas. The electrochemical etching setup includes a tube which seals the edges of the wafer preventing loss of the methanol. An electrolyte composed of 4:1 water: sulfuric is poured into the tube and the electrolyte replaces the wetting agent in the patterned holes. A working electrode is attached to a metal layer of the wafer, with reference and counter electrodes inserted in the electrolyte with all electrodes connected to a potentiostat. A single pulse on the counter electrode, such as a 100 ms pulse at +10.2 volts, is used to excite the electrochemical circuit and perform the etch. The process produces uniform etching of the patterned holes in the metal layers, such as chromium and molybdenum of the wafer without adversely effecting the patterned mask.

Inventors:
 [1];  [2];  [3];  [4]
  1. Menlo Park, CA
  2. Lake Oswego, OR
  3. Needham, MA
  4. Martinez, CA
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
873341
Patent Number(s):
6139716
Assignee:
Regents of University of California (Oakland, CA)
Patent Classifications (CPCs):
C - CHEMISTRY C25 - ELECTROLYTIC OR ELECTROPHORETIC PROCESSES C25F - PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
submicron; patterned; metal; etching; wet; chemical; process; holes; layers; electrochemical; wetting; agent; processed; wafer; etched; immersed; methanol; prior; inserting; setup; maintained; horizontal; transfer; maintain; film; covering; tube; seals; edges; preventing; loss; electrolyte; composed; water; sulfuric; poured; replaces; electrode; attached; layer; reference; counter; electrodes; inserted; connected; potentiostat; single; pulse; 100; 10; volts; excite; circuit; perform; etch; produces; uniform; chromium; molybdenum; adversely; effecting; mask; counter electrodes; electrodes connected; electrochemical etching; metal layers; chemical etching; metal layer; counter electrode; process produces; single pulse; wetting agent; chemical process; wet chemical; submicron patterned; patterned metal; /205/

Citation Formats

McCarthy, Anthony M, Contolini, Robert J, Liberman, Vladimir, and Morse, Jeffrey. Submicron patterned metal hole etching. United States: N. p., 2000. Web.
McCarthy, Anthony M, Contolini, Robert J, Liberman, Vladimir, & Morse, Jeffrey. Submicron patterned metal hole etching. United States.
McCarthy, Anthony M, Contolini, Robert J, Liberman, Vladimir, and Morse, Jeffrey. Sat . "Submicron patterned metal hole etching". United States. https://www.osti.gov/servlets/purl/873341.
@article{osti_873341,
title = {Submicron patterned metal hole etching},
author = {McCarthy, Anthony M and Contolini, Robert J and Liberman, Vladimir and Morse, Jeffrey},
abstractNote = {A wet chemical process for etching submicron patterned holes in thin metal layers using electrochemical etching with the aid of a wetting agent. In this process, the processed wafer to be etched is immersed in a wetting agent, such as methanol, for a few seconds prior to inserting the processed wafer into an electrochemical etching setup, with the wafer maintained horizontal during transfer to maintain a film of methanol covering the patterned areas. The electrochemical etching setup includes a tube which seals the edges of the wafer preventing loss of the methanol. An electrolyte composed of 4:1 water: sulfuric is poured into the tube and the electrolyte replaces the wetting agent in the patterned holes. A working electrode is attached to a metal layer of the wafer, with reference and counter electrodes inserted in the electrolyte with all electrodes connected to a potentiostat. A single pulse on the counter electrode, such as a 100 ms pulse at +10.2 volts, is used to excite the electrochemical circuit and perform the etch. The process produces uniform etching of the patterned holes in the metal layers, such as chromium and molybdenum of the wafer without adversely effecting the patterned mask.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {1}
}