| Budget Amount *help |
¥11,500,000 (Direct Cost: ¥11,500,000)
Fiscal Year 2004: ¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2003: ¥7,700,000 (Direct Cost: ¥7,700,000)
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| Research Abstract |
In this study, we developed a method detecting paramagnetic substances at very low concentration in a semiconductor utilizing electrically detected magnetic resonance (EDMR). The AC bias detection technique, which we newly developed, enabled to cancel the effects, such as Shottky barriers, that disturbed the ohmic contact between the electrodes and a sample material. Further, we certified that the AC bias current penetrated the thin surface layer of a sample such as silicon oxide, which normally obstructed a DC current. Using the AC bias, non-destructive EDMR measurements of part of a silicon wafer were realized. The EDMR spectrum obtained was the same as that when using a conventional method (i.e., DC bias). SNR was worse when AC bias was used ; however, because the noise appeared to be coming from outside, ample room exists to improve the sensitivity of the AC bias technique. This AC bias technique can be applied to measure various bulk materials ; in addition, it should be applicable to systems in which oxidization or reduction caused by a DC bias current corrupts the system.
We also proposed an open type RF resonator for ESR irradiation, and a procedure to obtain the signal intensity at the selected region, which were effective to observe EDMR.
Further, some advanced experimental results were obtained in this research. The EDMR images of a silicon plate were obtained under partial light illumination. We showed that EDMR imaging by localized illumination can be a tool by which the characteristics of semiconductors can be estimated. We also firstly observed EDMR spectra of compound semiconductor, which had very high band-gap energy by using UV light emitting diode illumination.
By these results, we made possible to observe EDMR of not only silicon semiconductor devices but also bulk various materials, such as a compound semiconductor non-destructively.
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