At 09:28 AM 3/11/98 -0500, you wrote:
>Forgive me if this has been discussed before, but I've been wondering for
>some time if there are viable ways to erase OTP PIC parts. I've heard
>discussion of X-Raying and prolonged baking in the past (here and from
>other lists), but none of them sound really practical or efficacious.
>
>My idea is this: has anybody considered exposing an OTP PICs to a steep
>E-field gradient? This is essentially what happens within EEPROM devices.
>Of course the gate oxide structure for EEPROMs is different from the
>structure EPROMs, but perhaps the same effect could be induced by clamping
>an OTP package between the plates of a capacitor with a suitable voltage
>ramp profile applied to those plates. With a high enough gradient it should
>be possible to get those trapped electrons to tunnel back where they came
>from.

I can't answer the question, instead, I have a more basic question: when
devices such as EPROM and EEPROM, which involve a floating gate, are
programmed, what is the source of the electrons which get transferred to
the gate? Do they come out of the oxide layer into the metal gate, or is
there another layer involved?

Sean

+--------------------------------+
| Sean Breheny                   |
| Amateur Radio Callsign: KA3YXM |
| Electrical Engineering Student |
+--------------------------------+
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