Method of manufacturing a self-aligned guard ring of a photo diode

A method of manufacturing a self-aligned guard ring of a photo diode comprising:

• providing a semiconductor substrate with a photo diode region defined on the semiconductor substrate, and an isolation matter surrounding the photo diode region;
• forming a first mask on the semiconductor substrate covering the isolation matter and exposing a part of the photo diode region;
• forming a spacer around the first mask;
• utilizing the first mask and the spacer as a block for performing a first ion implantation process to create a photo sensor inside the photo diode region in the semiconductor substrate;
• removing the spacer;
• forming a second mask on the semiconductor substrate where the semiconductor substrate is not covered by the first mask, and then removing the first mask;
• forming a third mask on the isolation matter outside edge and the third mask exposing the photo diode region;
• utilizing the second mask and the third mask as a block for performing a second ion implantation process to create a self-aligned guard ring surrounding the photo sensor;
• and
• removing the second mask and the third mask.

A method of manufacturing a self-aligned guard ring comprising:

• providing a semiconductor substrate with at least a device region defined on the semiconductor substrate;
• forming a first mask on the semiconductor exposing a part of the device region;
• forming a second mask on the semiconductor substrate where the semiconductor substrate is not covered by the first mask;
• removing the first mask;
• uniformly increasing the covering area of the second mask;
• forming a third mask on the surface of the semiconductor substrate and the third mask exposing the device region and the second mask;
• utilizing the second mask and the third mask as a block for performing a first ion implantation process to create a self-aligned guard ring;
• and
• removing the second mask and the third mask.

A method of manufacturing a self-aligned guard ring comprising:

• providing a semiconductor substrate with at least a device region defined on the semiconductor substrate;
• forming a first mask on the semiconductor exposing a part of the device region;
• uniformly shrinking the covering area of the first mask;
• forming a second mask on the semiconductor substrate where the semiconductor substrate is not covered by the first mask;
• removing the first mask;
• forming a third mask on the surface of the semiconductor substrate and the third mask exposing the device region and the second mask;
• utilizing the second mask and the third mask as a block for performing a first ion implantation process to create a self-aligned guard ring;
• and
• removing the second mask and the third mask.