Re: LEDs

[Brian Whatcott <betwys1@SBCGLOBAL.NET>]

At 07:10 PM 9/6/2004, you wrote:
> Is there someone here who knows the technology to fabricate an LED?
> Can you give an outline?
> And can you address the complication of making a blue LED?  Is it possible?
>
> TX
>
> Jim
> Jim Green
> mailto:JMGreen@sisna.com
> http://users.sisna.com/jmgreen

Lacking hands-on feedback.....
here's an old recipe for making LEDs, Jim.

Take a clean  wafer and apply a safety layer of silicon nitride to
obliterate pinholes left in the pre existing silicon dioxide coat.
RF plasma was the suggested method.
Etch out the silicon nitride from one surface, and deposit a 10 mu layer of
gallium arsenide. A graded layer of gallium arsenide phosphide is then applied
to complete the structure which is diced and encapsulated in a clear
plastic case,
 with holding electrodes.

This is essentially a transcription of TI's 1975 patent for a vapor
epitaxial method
for preparing LED wafers    USP# 4000020, due to Gartman, Wesley, Garland, TX.

The process for blue LEDs is much more recent, but I cannot offer details.


Brian Whatcott    Altus OK    Eureka!