Harald Bohlen

Electron beam proximity printing

Abstract Electron Beam Proximity Printing has been reported on several years ago. Meanwhile an experimental tool was built in IBM Sindelfingen. This paper presents some technical details, the resulting tool capabilities and some results achieved so far.

Mix-and-match EBP/optical lithography of 1 MBIT chips

Abstract Mix-and-match lithography between Electron Proximity Printing (EBP) and optical lithography was demonstrated in processing nine levels of a 1Mbit device up to first metallization. High overlay accuracy was achieved. For the first time we produced a large membrane stencil mask with the high pattern density of a standard 1Mbit chip.

Micropositioning for Submicron Electron Beam Lithography

Positional accuracy is the most important parameter in future lithography for integrated circuits. With shrinking dimensions it is a great challenge to meet the associated overlay requirements. Electron Beam Proximity printing is described as a lithography for future integrated circuit fabrication. A unique correction feature was developed for this exposure method which is applicable for many tool and mask related pattern distortions. Digital signal processor cards have been developed which can handle the large amount of data for corrections in real time during the exposure. Results of this exposure method on test devices are presented.

The electron beam proximity printing lithography, a candidate for the 0.35 and 0.25 micron chip generations

Abstract Following the trends in the semiconductor technology to higher density and smaller dimensions the light-optical tools get serious technical problems to solve the requirements on resolution, depth of focus and overlay. Besides exposure tools using DUV / excimer laser sources other technologies like e-beam and X-ray will follow. There are several requirements which have to be solved to demonstrate the capability of a lithography technique for the fabrication of ULSI circuits. Three of them, the 1. o mask technology. 2. o resolution of a high throughput exposure tool. 3. o registration capability for layer to layer overlay. will be addressed in this paper and will confirm that the Electron Beam Proximity Printing (EBP) technology can fulfill these requirements for the 64 Mbit and 256 Mbit chip generations with minimum linewidths of 0.35 and 0.25 micron respectively.