| 摘要 |
PURPOSE:To prevent a smear, a blooming, etc., and to obtain a sharp picture by forming an oxide layer approximately reaching an overflow drain layer under a transfer gate. CONSTITUTION:Predetermined positions in an N-type Si substrate 11 are etched through RIE to shape grooves 12a, 12b in depth of approximately 4.5mum. The grooves are filled with CVDSiO2 13a, 13b, and B ions are implanted selectively between the layers 13a and 13b and annealed to form P layers 14a, 14b. An epitaxial layer 15 is superposed and annealed, and a transfer gate section 16 is crystallized, and coated with an SiO2 film 17. An inter-element isolation layer 18 is shaped through selective oxidation, a gate oxide film 19 is formed, and P ions are implanted to the layer 14a to shape a buried channel 20 in thickness of approximately 1mum. A poly Si transfer electrode 21 is formed, and As ions are implanted to the P layer 14b and annealed to shape a photodiode 22. In the image pickup element, the oxide layer 13b reaching the N-type overflow drain 11 (the substrate) is formed under the transfer gate 16, thus preventing an inflow to the channel 20 of charges generated in the deep section of the element 22, then acquiring a distinct picture. |
