JPS63248159A - Semiconductor photodetector - Google Patents

Abstract

PURPOSE:To prevent an effect on an adjacent picture element when beams are projected to a picture element by forming a trench around the picture element. CONSTITUTION:A trench 5 is cut between a picture element 3 for a semiconductor photodetector and an adjacent picture element 4. The ions of phosphorus are implanted into the trench 5 and diffused to shape a gettering layer 6. Silicon dioxide is attached into the trench, and poly Si 8 is deposited onto silicon dioxide. When beams are projected to the picture element for the semiconductor photodetector constituted in this manner and charges are generated, charges do not transfer to the adjacent picture element in a shallow region because there exists the electrically insulated trench 5 between the picture element and the adjacent picture element. Since the layer 6 is shaped in a section lower than the trench 5, charges reaching to the layer 6 are annihilated in the layer 6. Accordingly, beams have no effect on the adjacent picture element.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a pixel in a semiconductor light receiving device used for transfer in a copying machine or the like.

[Summary of the invention]

This invention prevents generated carriers from affecting other pixels by providing a groove around the pixel in a semiconductor light receiving device and covering the lower part of the pixel with a gettered layer. It is.

(Prior Art) Conventionally, as shown in FIG. 2, a pixel 3 made up of P″1 and n−t has been known.

(Problem to be solved by the invention) However, in the conventional semiconductor light receiving device, even if light enters pixel 3, the charge that is not captured by that pixel will reach the neighboring pixel and affect it. There were drawbacks such as.

Therefore, in order to solve these conventional drawbacks, the present invention aims to prevent light from affecting neighboring pixels when light enters a pixel.

[Means for solving problems]

In order to solve the above problems, the present invention digs a groove between pixels, implants phosphorous ions into the groove, diffuses it, and creates a gettering layer under the groove, and further improves the depth of the groove. By attaching silicon dioxide to the walls and stacking polysilicon on top of it to close the grooves, they prevented light entering a pixel from affecting neighboring pixels.

[Effect]

Suppose that light enters a pixel of a semiconductor photodetector configured as described above and a charge is generated. Since there is an electrically insulated groove between this pixel and an adjacent pixel, it will not work in a shallow area. There is no charge going to the neighboring pixel. Furthermore, since there is a gettering layer below the groove, the charges that have reached this layer disappear in this layer.

Therefore, there is no effect on neighboring pixels.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

In FIG. 1, a groove 5 is dug between a pixel 3 and an adjacent pixel 4 of the semiconductor light receiving device. A gettering layer 6 is formed by implanting phosphorus ions into the liquid 5 and diffusing them. ? 1
Attach silicon dioxide to #5. Further, polysilicon 8 is stacked thereon.

In this way, by digging the groove 5 between the pixel 3 and the adjacent pixel 4 and providing the gettering layer 6, the movement of charges between the pixels is prevented.

〔Effect of the invention〕

As explained above, this invention has the effect of reducing the influence between pixels by digging a groove around the pixels and providing a gettering layer underneath.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a semiconductor light receiving device according to the present invention;
FIG. 2 is a longitudinal sectional view of a conventional semiconductor light receiving device. 1...Dark P region 2...N substrate 3...Pixel
4...Next pixel 5...N list
6...Gettering layer 7...Intermediate insulating layer 8
...Polysilicon 9...More than electrode

Claims (3)

[Claims] (1) A semiconductor light receiving device characterized by having a groove dug around a pixel. (2) The semiconductor light receiving device according to claim 1, further comprising a gettering layer provided below the pixel. (3) The semiconductor light-receiving device according to claim 1, wherein silicon dioxide is attached to the groove, and silicon is further stacked thereon.