Image sensor having integrated single large scale pixel and pixel separation pattern
View Patent ↗An image sensor is disclosed where individual photo diodes of the respective unit cells separated by an element isolating layer are physically integrated into a single large scale pixel formed widely on a semiconductor substrate so as to hold the pixels in common. A pixel separation pattern is additionally formed on a portion of the large scale photo diode formed so as to electrically separate them. An optimization of the light receiving area of the photo diode, a minimization of the intrusion area of an element isolating layer, and so on are achieved, so that the photo diode recovers an area occupied by an intrusion of the element isolating layer, thus maximizing the light receiving area in an optimal scale and easily preventing electrical impacts between the respective unit cells.
1. An image sensor comprising:
a photo diode formed on an active region of a semiconductor substrate, wherein said photo diode consists of a plurality of pixels and is formed by integrating the pixels into one pixel without being separated by an element isolating layer;
a pixel separation pattern formed on said photo diode and selectively driven depending upon input voltage, thus defining said photo diode into unit pixels; and
transistors for individually resetting the respective unit pixels defined by said pixel separation pattern, and individually transferring electron-hole pair stored in said respective unit pixels.
2. The image sensor according to claim 1 , wherein said pixel separation pattern consists of a first pattern for vertically separating said photo diode and a second pattern for horizontally separating said photo diode.
3. The image sensor as claimed in claim 2 , wherein said first pattern and said second pattern are electrically connected with each other.
4. The image sensor according to claim 2 , wherein said first pattern and second pattern are electrically disconnected with each other.
5. The image sensor according to claim 2 , wherein said pixel separation pattern is composed of poly silicon material.
6. The image sensor according to claim 1 , wherein said input voltage applied to said pixel separation pattern has negative electric potential.