| 摘要 |
A gas or ion sensor has a substrate (11) with a drain (3) and source (2) astride a channel (4) and a guard ring (1) outside the channel zone. A surface profile (7, 12) is located between the guard ring and the channel. The sensor has a sensitive gate layer (8) whose potential depends upon the surrounding gas or ion concentration. An air gap (10) is located between the gate layer and the channel. The profiled surface has peaks (7) and troughs (12) formed by a series of thick oxide layer deposits on the surface (15) between an insulating thin layer (13) on the channel and the guard ring. The peaks are at regular concentric intervals between the channel and guard ring. The sensitive gate layer is a gas-sensitive gate layer (8). |
