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Title: Method for photolithographic definition of recessed features on a semiconductor wafer utilizing auto-focusing alignment

Abstract

A method is disclosed for photolithographically defining device features up to the resolution limit of an auto-focusing projection stepper when the device features are to be formed in a wafer cavity at a depth exceeding the depth of focus of the stepper. The method uses a focusing cavity located in a die field at the position of a focusing light beam from the auto-focusing projection stepper, with the focusing cavity being of the same depth as one or more adjacent cavities wherein a semiconductor device is to be formed. The focusing cavity provides a bottom surface for referencing the focusing light beam and focusing the stepper at a predetermined depth below the surface of the wafer, whereat the device features are to be defined. As material layers are deposited in each device cavity to build up a semiconductor structure such as a microelectromechanical system (MEMS) device, the same material layers are deposited in the focusing cavity, raising the bottom surface and re-focusing the stepper for accurately defining additional device features in each succeeding material layer. The method is especially applicable for forming MEMS devices within a cavity or trench and integrating the MEMS devices with electronic circuitry fabricated on themore » wafer surface.« less

Inventors:
 [1];  [1];  [1];  [1];  [1]
  1. (Albuquerque, NM)
Issue Date:
Research Org.:
SANDIA CORP
OSTI Identifier:
871726
Patent Number(s):
5783340
Assignee:
Sandia Corporation (Albuquerque, NM) SNL
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; photolithographic; definition; recessed; features; semiconductor; wafer; utilizing; auto-focusing; alignment; disclosed; photolithographically; defining; device; resolution; limit; projection; stepper; formed; cavity; depth; exceeding; focus; focusing; located; die; field; position; light; beam; adjacent; cavities; provides; bottom; surface; referencing; predetermined; below; whereat; defined; material; layers; deposited; build; structure; microelectromechanical; mems; raising; re-focusing; accurately; additional; succeeding; layer; especially; applicable; forming; devices; trench; integrating; electronic; circuitry; fabricated; material layer; electronic circuit; semiconductor wafer; light beam; semiconductor device; electronic circuitry; bottom surface; material layers; mems device; wafer surface; predetermined depth; semiconductor structure; device features; /430/356/438/

Citation Formats

Farino, Anthony J., Montague, Stephen, Sniegowski, Jeffry J., Smith, James H., and McWhorter, Paul J. Method for photolithographic definition of recessed features on a semiconductor wafer utilizing auto-focusing alignment. United States: N. p., 1998. Web.
Farino, Anthony J., Montague, Stephen, Sniegowski, Jeffry J., Smith, James H., & McWhorter, Paul J. Method for photolithographic definition of recessed features on a semiconductor wafer utilizing auto-focusing alignment. United States.
Farino, Anthony J., Montague, Stephen, Sniegowski, Jeffry J., Smith, James H., and McWhorter, Paul J. Thu . "Method for photolithographic definition of recessed features on a semiconductor wafer utilizing auto-focusing alignment". United States. https://www.osti.gov/servlets/purl/871726.
@article{osti_871726,
title = {Method for photolithographic definition of recessed features on a semiconductor wafer utilizing auto-focusing alignment},
author = {Farino, Anthony J. and Montague, Stephen and Sniegowski, Jeffry J. and Smith, James H. and McWhorter, Paul J.},
abstractNote = {A method is disclosed for photolithographically defining device features up to the resolution limit of an auto-focusing projection stepper when the device features are to be formed in a wafer cavity at a depth exceeding the depth of focus of the stepper. The method uses a focusing cavity located in a die field at the position of a focusing light beam from the auto-focusing projection stepper, with the focusing cavity being of the same depth as one or more adjacent cavities wherein a semiconductor device is to be formed. The focusing cavity provides a bottom surface for referencing the focusing light beam and focusing the stepper at a predetermined depth below the surface of the wafer, whereat the device features are to be defined. As material layers are deposited in each device cavity to build up a semiconductor structure such as a microelectromechanical system (MEMS) device, the same material layers are deposited in the focusing cavity, raising the bottom surface and re-focusing the stepper for accurately defining additional device features in each succeeding material layer. The method is especially applicable for forming MEMS devices within a cavity or trench and integrating the MEMS devices with electronic circuitry fabricated on the wafer surface.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {1}
}

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