A charge-coupled device (CCD) area image sensor has been demonstrated with an experimental 16 x 16 prototype.
It is a frame transfer CCI (charge-coupled imager) using two-phase, overlapping polysilicon/polysilicon and polysilicon/aluminum gates. In this device, ion implanted barriers are used for two-phase CCD, and NMOS process has been adopted.
The driving clocks for the CCD image sensor are generated using two 2708 ROMs and several IC's, and the output image produced by the image sensor is displayed in the oscilloscope.
The transfer inefficiency of the output register has been measured about 1%-1.45% for 50KHz-200KHz frequency range.
The FDA (Floating Diffusing Amplifier) method, which is the most popular approach for the detection of output signal, is used as the charge detection scheme. The operation and characteristics of the CCD area image sensor has been discussed in detail.
analog 신호 처리 능력을 가지고 있는 charge-coupled device를 이용하여 n-channel 16X16 CCD area image sensor 를 제작하였는데, 이 소자는 overlapping poly/poly,poly/Al gate와 ion-implanted barrier를 갖는 2-phase,frame-transfer 방식이다.
제작된 감지소자를 이용하여 alphabet 등을 image source 로 하여 오실로스코우프에 display 하여 출력영상을 얻었고 output reg. 를 사용하여 주파수 변화에 대한 전하이동 손실의 변화를 측정하였다.
그 결과는 50 KHz 와 100 KHz사이에서는 ε= 0.93% 로 유지되나, 주파수가 100 KHz 를 넘어서면 loss가 증가하기 시작하여 200 KHz 에서는 1.45%가 되었다.
그러나 chnnel length 를 줄이고 적절한 process 를 수행하면 전하이동 효율을 향상시킬수 있으리라 생각한다.
