CCD-world: AMP LUMINESCENCE

[MYPIXEL at aol.com]

The following was posted to CCD-world:

In a message dated 10/24/99 4:12:23 PM Pacific Daylight Time, 
Venkat_Iyer at Reticon.egginc.com writes:

<< 
 "I'm curious about dark current being generated by your amplifier. Are
 you 
 sure the source isn't luminescence? The problem is common with dual
 stage 
 amplifiers where on-chip load MOSFETs are utilized."
 
 I have no idea of this luminescence problem.  Can anyone give me a
 reference or explain what this effect is ?
 
 Thanks. >>


*****************************jj
If you see a hot corner in amplifier region ..  .  then it is likely 
luminescence ..  . . (not dark current). 

There are three potential luminescence sources. . .  .

1). Pinchoff luminescence is related to the pinchoff region of the MOSFET. 
The effect can be seen in long integrations when the VDD is a few volts above 
pinchoff (i.e., VDD + VEFF where VEFF is the effective threshold of 
amplifier).

2). Difussion luminescence. Premature breakdown of the VDD diffusion. Common 
with non LDD amplifiers.

3). Load  luminescence. On-chip MOSFET loads for dual stage amps can easily 
luminescence if operated beyond pinchoff (common  . . . . unless they are 
processed properly).

It would help to know what type of CCD you are running. .  . LDD? Dual stage? 
EEV? SITe? etc.

Does signature vary with VDD?

thanks,

**********************************************jj
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