摘要:
The invention relates to a phase shift mask for lithographically producing small structures at the limit of a resolution that is predetermined by the wavelength of the exposure radiation. The phase shift mask has first regions A and second regions B that effect a phase-shift relative to the first regions. The second regions are arranged beside the first regions for producing a sudden phase shift along the boundaries between the first and the second regions. Individual first regions touch one another via corners at points, at which the second regions also touch one another via corners. The result is that the boundaries between first and second regions merge at these points and these points are opaque to the radiation. The invention makes it possible to expose extremely small contact holes with just a single exposure and thus leads to a reduction of costs in the fabrication of integrated semiconductor circuits.
摘要:
A shading film of chrome is formed entirely on one surface of a circular substrate of quartz. The substrate is rotated and resist is applied to the shading film. Since the substrate is shaped in a circle, the resist spreads uniformly on the entire surface of the shading film by the centrifugal force. Therefore, the resist has a substantially uniform film thickness over almost the entire surface of the shading film. This resist is patterned to form a resist pattern. By etching the shading film with the resist pattern used as a mask, a pattern preferable in accuracy of dimensions can be formed.
摘要:
The photolithographic etching of contact holes in trenches in an insulator layer over a silicon body is improved by adjusting properly the depth of the trench and the thickness of the photoresist used in the photolithography.
摘要:
A lithographic system with improved control of critical dimensions (CD). The lithographic system includes a detector for determining the amount of energy absorbed by the photoresist. This enables the lithographic system to expose each field with the required exposure dose, thus reducing variations in CD.