Methods, photoresists and substrates for ion-implant lithography
View Patent ↗New photoresists are provided that can be applied and imaged with reduced undesired outgassing and/or as thick coating layers. Preferred resists of the invention are chemically-amplified positive-acting resists that contain photoactive and resin components.
1. A method for providing an ion-implanted semiconductor substrate comprising:
providing a semiconductor substrate having coated thereon a relief image of chemically-amplified positive-acting photoresist composition,
wherein the photoresist comprises a resin that comprises, prior to photoactivation, photoacid-labile moieties that are spaced by at least 2 atoms from the resin backbone; and
applying dopant ions to the substrate.
2. The method of claim 1 wherein the photoresist composition has been applied to the wafer, exposed to patterned radiation having a wavelength of 248 nm, and developed to provide the relief image.
3. The method of claim 2 wherein the photoresist comprises a resin that comprises, prior to photoactivation, photoacid-labile moieties that are spaced by at least 3 atoms from the resin backbone.
4. The method of claim 2 wherein he photoresist comprises a resin that comprises, prior to photoactivation, photoacid-labile moieties that are spaced by at least 4 atoms from the resin backbone.
5. The method of claim 2 wherein he photoresist comprises a resin that comprises, prior to photoactivation, photoacid-labile moieties that are spaced by at least 6 atoms from the resin backbone.
6. The method of claim 2 wherein the dopant ions are boron, arsenic or phosphorus ions.