| 摘要 |
A method of depositing patterned thin films on an integrated circuit substrate which comprises first forming a layer of positive photoresist material on the substrate and then heating to partially cure the photoresist while maintaining the surface of the photoresist interfacing with the substrate at a lower temperature than the opposite surface of the photoresist which is being exposed to the heat. As a result of this expedient, the upper or exposed portion of the photoresist layer is cured to a greater extent than the lower portion at the interface with the substrate. Then, the photoresist layer is exposed to a selected pattern of light, after which developer for the photoresist material is applied. The developer will remove the less cured interfacing portion of the photoresist layer at a higher rate than the more cured upper layer to thereby form an aperture pattern through the photoresist layer corresponding to the light pattern wherein the apertures are respectively narrower at the opposite or exposed surface than at said interfacing surface. This produces the negative slope or "overhang" type lift-off mask which is considered to be critical to forming thin film patterns by lift-off techniques. Then, the selected thin film is deposited onto said substrate through the apertures utilizing the photoresist mask as a deposition mask, after which the remainder of the photoresist layer is removed, leaving the thin film pattern on the substrate. |
