| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable-capacitance diode that can obtain a large capacitance change ratio using low-voltage drive. SOLUTION: An N-type impurity having a high concentration is ion-implanted to a P-type region 11 with a field oxide film 12 formed on the P-type region 11 having a low impurity concentration as an implantation mask, and an N-type region 14 having a high impurity concentration is formed. Then, a P-type impurity having a middle concentration is ion-implanted to the P-type region 11 with the field oxide film 12 as an implantation mask for forming a P-type region 15 having an intermediate impurity concentration. At this time, a semiconductor substrate is inclined so that an incident angleθof an ion beam becomes 25°, and the semiconductor substrate is rotated, thus narrowing the depth of the P-type region 15, reducing a reverse-bias voltage required for expanding a depletion layer from the P-type region 15 to the P-type region 11, and hence obtaining a large capacity change ratio using low-voltage drive. COPYRIGHT: (C)2004,JPO
|
