Interpolation is necessary to correct for distortions caused by the small, though finite distances, that separate the four individual sensors that make up each pixel. The result of this interpolation is often a great increase in the size of the original digital image; often this increase in data size is three-fold. Along with this increase in size, interpolation can compromise the integrity of the original data if performed prior to storage.
Second, after the step of interpolation, the digital image data is often compressed prior to storage. Compression is necessary often because of the increase in size after the interpolation function just discussed, as well as to facilitate transmission through systems of limited bandwidth, such as television systems. However, in compression methods commonly used, once a digital image has26, which are uncoupled bonds of the silicon atoms. The vacancy type defects remaining in the vicinity of the metallurgical junction 25 are raised to an energy level within the energy bandgap by the presence of the dangling bonds, thereby generating junction leakage current due to this energy level. The junction leakage current reduces the charge storage capability of the memory cell, as described above.
Patent Publication JP-A-1(1989)-32640 describes a technique for reducing the leakage current which may otherwise increase in the vicinity of the dopant diffused region along with a smaller depth thereof. In this publication, by using implantation of fluorine together with a heat treatment, the traps are reduced by the fluorine in the vicinity of the diffused region, to thereby reduce the leakage current in the