Microcircuit fabrication
US4451738A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 24, 1981 |
| Grant date | May 29, 1984 |
| Priority date | — |
| Expiry date | Jul 24, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The fabrication of a microcircuit by beam lithography requires an economic distribution of processing time between the high resolution portions of the exposure pattern and areas of much lower resolution. At least one ion beam provides the high resolution performance and at least one electron beam satisfies the lower resolution requirement. The beams are independently operable and are relatively inclined for substantial convergence at the substrate. The convergence is such that all beams can be scanned simultaneously in a single elemental area of substrate or in adjacent elemental areas which are presented for exposure in sequence. For registration the substrate is imaged by electron scanning and the positions of registration marks are related in the image to predetermined positions which represent the required position of the substrate. A positional correction signal is derived by observation of image brightness, size and orientation at the predetermined positions. The signal is processed by a computer which holds all positional control and scan control data and instructs the relevant controls.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.