Abstract: A mask which is resistant to a plasma etching treatment is formed by providing an etch resistant skin over a lithographically patterned radiation sensitive resist film present on a substrate. The etch resistant skin is formed by providing a layer of, for example, chromium on the patterned resist and on the exposed surface of the substrate, and then, baking so that the chromium reacts chemically with the resist to form the etch resistant skin around the patterned film. This method may be used for example to manufacture a photo mask using a chromium coated glass substrate, or during the manufacture of semiconductor devices on a semiconductor wafer substrate.

Abstract: A mask which is resistant to a plasma etching treatment is formed by lithographically patterning a radiation sensitive film present on a substrate. The etch resistance of the mask is enhanced by exposure to a carbon monoxide plasma which forms a region with an enhanced etch resistance over the surface of the patterned film. This method may be used, for example, to manufacture a photomask using a chromium coated glass substrate, or during the manufacture of semiconductor devices on a semiconductor wafer substrate.

Abstract: A semiconductor substrate is mounted in an electron beam image projector with a mask. The patterned electron beam from the mask comprises a first sub-pattern and a second lower intensity sub-pattern. The difference in the intensities of the two sub-patterns permits the automatic alignment of the patterned electron beam relative to the substrate by detecting when the first sub-pattern is incident on a reference marker pattern on the substrate, while the first and second sub-patterns together expose an electron sensitive layer at the entire area of the reference marker pattern. The part of the layer retained after developing can be used as an etchant mask during the definition of a protective layer or the removal of unwanted material from the entire area of the reference marker pattern depending on whether the layer is a negative or a positive electron sensitive material.

Abstract: An alignment marker on a substrate surface is covered with polycrystalline semiconductor material during the growth of an epitaxial layer on the monocrystalline substrate. This polycrystalline material is then removed with a selective etchant to re-expose the marker for use in defining an area for processing at the epitaxial layer surface. Permits accurate alignment between buried layers and regions formed from the epitaxial layer surface. Permits provision of the marker on the substrate when it is undesirable to provide the marker on the epitaxial layer surface. Particularly advantageous for electron image projection exposure of electron-sensitive resists.