Method for experimentally verifying imaging errors in photomasks

摘要

The method enables determining imaging errors of photomasks for the lithographic structuring of semiconductors. A latent image of the mask is first produced in a photoactivatable layer by exposure. After heat treatment carried out for increasing the contrast and development of the exposed resist, the latter is treated with an amplification agent which preferably diffuses into the exposed parts of the photoresist. There, it reacts with groups of the photoresist, which leads to an increase in the layer thickness of the resist in the exposed parts. A topographical image of the surface of the photoresist, which can be created, for example, by scanning electron microscopy, then indicates imaging errors by protuberances which are located outside the image of the mask. The mask layout can be tested under production conditions and the adjustment and the checking of all components of the phototransfer system used for the production of microchips is facilitated.