TDDB (Time Dependent Dielectric Breakdown) lifetime has been one of the main factors for this evaluation. In this case, a wafer is destroyed in order to be evaluated, which reduces the semiconductor yield. To solve this problem, we propose a new technique for the evaluation of the gate insulator which is a non-destructive and contactless measurement method, and thus an appropriate method for inline processes. A voltage is applied on a Si/SiO2 specimen. A voltage source electrode and the specimen are not in contact (10micron gap). After it is charged, the specimen is irradiated by a xenon-flash-lamp. Since the energy of this pulsed light is beyond 4eV, electrons are emitted and move from Si to SiO2. It is possible to estimate the condition (the electrical conductivity) of the insulator using this phenomenon. A multi-electrode system was developed for mass production. With this system, one is able to evaluate 10 thousand points over a 12-inch wafer in 1 minute. |
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CITATIONS
Cited by 1 scholarly publication.
Semiconducting wafers
Oxides
Semiconductors
Dielectrics
Nondestructive evaluation
Silicon
Reliability