Method of making CCD imagers with reduced defects
AssigneeRCA Corporation
InventorLubomir L. Jastrzebski
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Abstract
In a method of making a CCD imager on a semiconductor wafer, it is usual to have the imagers spaced from the outer periphery of the wafer. The method includes a sequence of steps including masking the appropriate surface of the wafer, defining openings in the mask and forming doped regions in the wafer through the opening. In accordance with this invention, the region of the semiconductor wafer adjacent the outer periphery is not doped during any doping steps. It has been found that with this method, dislocations do not nucleate and propagate into the area of the wafer where the CCD imagers are to be formed and that white spots and lines in the visual image formed from the imager are significantly reduced.
Claims8
In a method of making a large scale integrated circuit device on a semiconductor wafer with said device being spaced from the outer periphery of said wafer, said method including the following sequence of steps:
- masking a surface of said wafer;
- defining openings in the mask;
- and forming doped regions of semiconductor material through said openings;
- the improvement comprising:
- preventing dopants from being deposited into the region of said surface adjacent said periphery.
In a method of making a CCD imager including a photosensing register and a temporary storage register each including a plurality of channels, an output register and an output transistor and further including appropriately doped channel stops and excess charge drains, said method including the steps of forming an oxide layer over one surface of a semiconductor wafer, depositing a photoresist over said oxide layer, defining openings in said oxide layer and said photoresist and depositing dopants into the regions of said wafer adjacent said openings, the improvement comprising:
- preventing dopants from being deposited into the region of said surface adjacent said periphery.
Dependencies are inferred from the claim text.