Browse Prior Art Database

Instrument for Selective Modification of Planar Circuits

IP.com Disclosure Number: IPCOM000052437D
Original Publication Date: 1981-Jun-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Romankiw, LT: AUTHOR [+2]

Abstract

Reference [1] discusses the general concept of the scanning acoustic microscope. In reference (2], the use of focused high frequency ultra sound for the selective deposition of gold is reported. Here, those concepts are used in an ultrasonic, electroplating instrument for the selective repair or modification of circuit conductors, such as are found on integrated circuit chips. The instrument can be used for the elimination of detected defects or for making engineering changes.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 68% of the total text.

Page 1 of 1

Instrument for Selective Modification of Planar Circuits

Reference [1] discusses the general concept of the scanning acoustic microscope. In reference (2], the use of focused high frequency ultra sound for the selective deposition of gold is reported. Here, those concepts are used in an ultrasonic, electroplating instrument for the selective repair or modification of circuit conductors, such as are found on integrated circuit chips. The instrument can be used for the elimination of detected defects or for making engineering changes.

In its simplest form, the instrument consists of a scanning acoustic microscope with variable acoustic power and an immersion sample holder containing an electrolyte which also serves as the acoustic medium. The electrolyte is chosen so that the plating or etching of material is severely limited by diffusion or passivation at the surface under normal conditions. However, in the presence of strong ultrasonic agitation, or even cavitation, the mass transport rate is increased by orders of magnitude.

The operating mode of the instrument is to scan the image at low acoustic power to select a spot for modification, then to position the acoustic beam there to apply plating or etching potential, and next to increase the acoustic power to a high level which enhances mass transfer when electroplating. The instrument can inspect in the scanning mode.

The scanning and high power acoustic frequencies need not be the same. Scanning can require a h...