Browse Prior Art Database

Removal of Metal Masks by Ultrasonic Agitation

IP.com Disclosure Number: IPCOM000090303D
Original Publication Date: 1969-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Slayton, G: AUTHOR

Abstract

In the fabrication of semiconductor devices, it is necessary to use metal masks in contact with the substrate for certain fabrication steps. For example, metal masks are used to define the contact areas onto which the contact metals are vapor-deposited. If the metal mask is just pried off after such a deposition, there is a tendency for the mask to tear away a portion of some of the contacts, resulting in nonuniform contacts. The mask can be cleanly removed by immersing the structure in a liquid, such as trichloroethylene or isopropyl alcohol, and then subjecting the liquid to ultrasonic agitation. The wafer separates without affecting any of the contact depositions.

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Removal of Metal Masks by Ultrasonic Agitation

In the fabrication of semiconductor devices, it is necessary to use metal masks in contact with the substrate for certain fabrication steps. For example, metal masks are used to define the contact areas onto which the contact metals are vapor-deposited. If the metal mask is just pried off after such a deposition, there is a tendency for the mask to tear away a portion of some of the contacts, resulting in nonuniform contacts. The mask can be cleanly removed by immersing the structure in a liquid, such as trichloroethylene or isopropyl alcohol, and then subjecting the liquid to ultrasonic agitation. The wafer separates without affecting any of the contact depositions.

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