Browse Prior Art Database

Controlled Shaping of Dry Etched Silicon Structures

IP.com Disclosure Number: IPCOM000116648D
Original Publication Date: 1995-Oct-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Bartha, J: AUTHOR [+4]

Abstract

Disclosed is a process for controlling the shape of dry etched silicon structures.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 85% of the total text.

Controlled Shaping of Dry Etched Silicon Structures

      Disclosed is a process for controlling the shape of dry etched
silicon structures.

      Structures having a completely isotropic profile or structures
showing nearly vertical (anisotropic) profiles can relatively simply
be formed in silicon substrates by means of plasma etching.

      However, there are applications where a sequential combination
of isotropic and anisotropic profiles may be advantageous.  For other
applications profiles showing an angle of approximately 45 degrees
are necessary.  For those profiles more or less costly approaches
were made.

      This article therefore describes a method to form profiles
having an angle of approximately 45 degrees by a sequential change
between isotropic and anisotropic etching steps.  The ratio
anisotropic/isotropic is thereby controlled by adding O(2) to the
basic gaseous component SF(6).

Using the following parameters, an isotropic profile could be
achieved:
  - Pressure:      10 &mu.bar
  - Gas Flow:     20 sccm SF[6]
  - Power:         1500 W microwave
  - Bias:           -25 V DC
  - Substrate
    Temperature:  -110 degrees C

      By adding, e.g., 4 sccm of O(2) and maintaining the other
parameters, anisotropic etch characteristics could be achieved.  When
operating these two "etching modes" alternatively, e.g., 2 minutes
etching without O(2), 2 minutes etching with the addition of O(2), a
positiv...