Browse Prior Art Database

Photoresist Process For High Current Ion Implant Processing

IP.com Disclosure Number: IPCOM000051753D
Original Publication Date: 1981-Mar-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Bauer, EH: AUTHOR [+5]

Abstract

State-of-the-art photoresist processes call for the addition of a crosslinking polymer to the photoresist solution in order to render the photoresist coat capable of withstanding ion beam currents in excess 1 mA. Although this results in a somewhat improved photoresist mask, it is only applied with limited success. Typically, when the photoresist-coated wafers are subjected to high intensity ion beams, the photoresist coat tends to blister and lift off, even with the addition of the cross-linking polymer, resulting in a high rework level and, at times, total destruction. In addition, it has been found that post ion-implant cracking of the photoresist coat increases the average rework level.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 73% of the total text.

Page 1 of 1

Photoresist Process For High Current Ion Implant Processing

State-of-the-art photoresist processes call for the addition of a crosslinking polymer to the photoresist solution in order to render the photoresist coat capable of withstanding ion beam currents in excess 1 mA. Although this results in a somewhat improved photoresist mask, it is only applied with limited success. Typically, when the photoresist-coated wafers are subjected to high intensity ion beams, the photoresist coat tends to blister and lift off, even with the addition of the cross-linking polymer, resulting in a high rework level and, at times, total destruction. In addition, it has been found that post ion-implant cracking of the photoresist coat increases the average rework level.

High current ion implants (e.g., I(B) > 1 300 muA) are employed where high doses (e.g., > 10/15/ ions/cm/2/) have to be achieved in relatively short process times to maintain a throughput rate of > 1 wafer per hour. Typical emitter ion- implant processes call for a dose of 9.5 X 10/15/ ions/cm/2/ at a throughput rate of > 20 wafers per hour. In order to achieve this dose at the stated throughput rate, beam currents of > 2mA typically have to be employed. Blistering of the photoresist coat when subjected to this dose rate represents a process yield impediment.

The following process was developed to overcome these photoresist limitations and make high current ion implant a more viable technique for ion implantation: 1....