Image sensor having improved spectral response uniformity

Active solid-state devices (e.g. – transistors – solid-state diode – Field effect device – Charge transfer device

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C257S233000, C257S445000, C257S448000, C438S075000, C438S078000, C438S079000

Reexamination Certificate

active

06489642

ABSTRACT:

FIELD OF THE INVENTION
The invention relates generally to the field of image sensors, and more particularly to electrode structures used in MOS devices.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,798,542 issued Aug. 25, 1998 to Anagnostopoulos et al. shows an image sensor having photosensors with first and second regions. Each region includes a stack of transparent layers, including a gate dielectric layer, transparent electrode layers, isolation layers and passivation layers over a semiconductor substrate. The spectral response of the photosensors is strongly affected by the layer materials and their relative thicknesses. As a result, the spectral response of the image sensor to incident light varies with wavelength, producing a spectral response curve with peaks and valleys. This problem can be particularly acute when the stack of transparent layers are identical for both regions.
There is a need therefore for an image sensor having improved spectral response uniformity.
SUMMARY OF THE INVENTION
The need is met according to the present invention by providing an image sensor, that includes a semiconductor substrate; a photosensor having, a first photosensing region including a first stack of one or more layers of transparent materials overlying the substrate, the first photosensing region having a spectral response having peaks and valleys, and a second photosensing region including a second stack of one or more layers of transparent materials overlying the substrate, the second photosensing region having a spectral response having peaks and valleys; and wherein at least one peak or valley of the spectral response of the first region is matched to at least one valley or peak respectively of the spectral response of the second region such that the average spectral response of the photosensor is smoother than the individual spectral response of either the first or second photosensing regions.
Advantages:
The image sensor has the advantage that the spectral response uniformity is improved. As a result, when color filters are added to the image sensor to produce a color image sensor, the uniformity of the color response of the sensor is greatly improved.


REFERENCES:
patent: 5442207 (1995-08-01), Jeong
patent: 5483090 (1996-01-01), Kitamura et al.
patent: 5798542 (1998-08-01), Anagnostopoulos et al.
patent: 5804845 (1998-09-01), Anagnostopoulos et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Image sensor having improved spectral response uniformity does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Image sensor having improved spectral response uniformity, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Image sensor having improved spectral response uniformity will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-2995190

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.