Browse Prior Art Database

Enhancing the Temperature Rise of Beam Addressable Memory Materials

IP.com Disclosure Number: IPCOM000078896D
Original Publication Date: 1973-Apr-01
Included in the Prior Art Database: 2005-Feb-26
Document File: 3 page(s) / 27K

Publishing Venue

IBM

Related People

Nethercot, AH: AUTHOR [+3]

Abstract

One of the major problems in obtaining a successful beam addressable memory (BAM) material, is the limitation imposed by the available power from GaAs laser diodes. To obtain sufficient energy for "writing" or "erasing" on the active memory material such as TeGeAs alloys, the laser beam must typically be on for a time of the order of 50-100 nsec or longer. Studies on the thermal profiles of such materials (i.e., temperature vs time) indicate that most of the incident energy is not utilized in raising the temperature of the memory material, but rather, goes into heating of the substrate.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 53% of the total text.

Page 1 of 3

Enhancing the Temperature Rise of Beam Addressable Memory Materials

One of the major problems in obtaining a successful beam addressable memory (BAM) material, is the limitation imposed by the available power from GaAs laser diodes. To obtain sufficient energy for "writing" or "erasing" on the active memory material such as TeGeAs alloys, the laser beam must typically be on for a time of the order of 50-100 nsec or longer. Studies on the thermal profiles of such materials (i.e., temperature vs time) indicate that most of the incident energy is not utilized in raising the temperature of the memory material, but rather, goes into heating of the substrate.

It is thus desirable to choose a substrate material which has a minimum thermal conductivity, in order to approach the so-called thermal adiabatic limit,
i.e., that situation in which the substrate conducts no heat at all. So far the lowest conductivity materials that have been used as substrates are MYLAR* and KAPTON.* However, even here substantial heat losses are encountered in the substrate material. These losses can be substantially reduced by decreasing the effective interfacial contact area between the memory material and the substrate, or by producing microscopic voids in the substrate. It is the latter effect which is the essence of the present description.

Techniques exist by which compounds containing diazo groups can be coated onto MYLAR or other organic materials. Layer thicknesses can be controlled to desired tolerances. By appropriate heat or light treatment, the diazo compounds can be made to dissociate interstitially to give nitrogen gas which is trapped as microscopic bubbles. The resulting substrate material will then consist of a layer of low-mass density of highly thermally insulating (K) and low- heat capacity (C) material, onto which the active memory material may then be deposited.

The re...