Browse Prior Art Database

Procedure for Resist Sensitivity Enhancement Via Polymer Film Morphology Control

IP.com Disclosure Number: IPCOM000050199D
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 58K

Publishing Venue

IBM

Related People

Kaufman, FB: AUTHOR [+2]

Abstract

Polystyrene tetrathiafulvalene (PSTTF) and selected other charge-transfer negative resists operate via light-induced ionization, forming dimeric crosslinks which lead to insolubilization of the irradiated polymer film. Normal post-irradiation processing involves solvent development with THF, an excellent solvent for the unirradiated regions. Spectroscopic studies of such irradiated films reveal an absorption at 8,000 Angstroms which increases in intensity with increasing irradiation time (Fig. 1).

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 72% of the total text.

Page 1 of 2

Procedure for Resist Sensitivity Enhancement Via Polymer Film Morphology Control

Polystyrene tetrathiafulvalene (PSTTF) and selected other charge-transfer negative resists operate via light-induced ionization, forming dimeric crosslinks which lead to insolubilization of the irradiated polymer film. Normal post- irradiation processing involves solvent development with THF, an excellent solvent for the unirradiated regions. Spectroscopic studies of such irradiated films reveal an absorption at 8,000 Angstroms which increases in intensity with increasing irradiation time (Fig. 1).

It is reasonable, however, to assume that photoconversion to the dimer from the initially produced monomer cation is not a process which goes with 100% efficiency. In addition, it has been recently found experimentally that the resist thickness remaining depends on the amount of (spectroscopically observed) dimer crosslinks produced.

These points suggest that post-irradiation treatments which cause an increase in the amount of dimer formed would result in an enhancement of the resist sensitivity to radiation.

To test this hypothesis, an exposed PSTTF film showing dimer absorptions (see A, Fig. 2) was washed with H(2)O, a polar nonsolvent for the irradiated film. After this treatment the film's absorption spectrum was found to have changed dramatically (see B, Fig. 2), indicating the formation of significantly more dimeric species. It is suggested that this kind of polar nonsolvent treatmen...