| 摘要 |
PROBLEM TO BE SOLVED: To realize a ring oscillator which is capable of accurately evaluating the life span of hot carriers in an N-channel MOS transistor. SOLUTION: 101 inverters formed of CMOSs are connected to a ring oscillator which evaluates the life span of hot carriers in a MOS transistor formed on a TEG, and the output of the inverters is fed back to the ring oscillator. The gate length L1 of the gate electrode 11b of an N-channel MOS transistor 4 is 0.5μm or so, and on the other hand, the gate length L2 of the gate electrode 11a of a P-channel MOS transistor 3 is 0.8 to 1μm, and the gate width W1 of the gate electrode 11a is formed at the same magnification with the gate length L2 , so that the P-channel MOS transistor 3 is less deteriorated, and an change of the N-channel MOS transistor 4 in characteristics due to deterioration can be surely detected.
|
