Bell Telephone Laboratories

At&t Bell Laboratories

David H Auston

Thirumalai N Venkatesan

Jene A Golovchenko

Richart Elliott Slusher

Peter Roland Smith

Clifford M Surko

Direct measurements of electronic device and material response times are made by using high speed photoconductors as both pulse generators and sampling gates.

Apparatus and method for measuring electronic response of high speed

A high speed photodetector using an amorphous semiconductor, such as silicon, and having a localized state density of at least 10.sup.18 /cm.sup.3 is described. The amorphous silicon may be prepared by evaporation or chemical vapor deposition or sputtering.

High speed photodetector

A new mode of optical annealing is disclosed wherein two different wavelength pulses are used to anneal a damaged semiconductor substrate. The first pulse may be of relatively weak intensity, but is strongly absorbed by the solid substrate. The second pulse, which is not strongly absorbed by the solid substrate when in the solid phase, is strongly absorbed by the substrate when in the molten phase. Exposure to the first pulse results in the melting of the substrate, which then becomes highly absorptive to light at the wavelength of the second pulse. Readily available laser sources which are generally not highly absorbed by the semiconductor in the solid phase may thus be efficiently utilized.

Dual wavelength optical annealing of materials

Polycrystalline and amorphous semiconductors can be annealed using a laser or electron beam to restore or obtain crystal order by epitaxial regrowth on a crystal substrate. When the annealing occurs by liquid phase epitaxy, the presence and lifetime of a molten state at the region being annealed can be used to control the annealing process. Various control mechanisms are described.

Growing community of inventors

Mountainside, NJ, United States of America

David H Auston