Noncontact Measurement of Generation Lifetime

Abstract

In this paper, we discuss the measurement of minority carrier generation lifetime by the noncontact metal-insulator-semiconductor (MIS) method. This method enables electrical measurements on metal-air-insulator-semiconductor (MAIS) structure utilizing the air gap and is based on the conventional MIS theory. Capacitance-time ( C-t) measurement is employed for the lifetime evaluation in this method. The generation lifetime and the surface generation velocity are determined by Zerbst analysis, similar to the case of a conventional MIS capacitor formed with gate electrodes. For Si substrate with a long lifetime, the conventional MIS method has the disadvantage of long measurement time. However, MAIS structure reduces the measurement time by increasing the air gap distance. This is because the air gap is equivalent to a thick oxide film. In our experiment, metal-contaminated Si wafers were used to compare the MAIS method with the conventional MIS method in terms of the generation lifetime. The experimental results obtained from the two methods showed good agreement.

Physical understanding and technological control of carrier lifetimes in semiconductor materials and devices: A critique of conceptual development, state of the art and applications

“…Pulsing the MOS capacitor into deep depletion, the capacitance-time (C-t) curve is recorded [104][105][106][107][108][109][110][111][112][113][114]. The capacitance relaxation is governed by thermal generation of electron-hole pairs.…”

Characterization of Generation Lifetime and Surface Generation Velocity of Semiconductor Wafers by a Contactless Zerbst Method

“…In this study, the generation lifetime and the surface generation velocity were characterized by combining the Zerbst method with contactless electrical characterization techniques that use a metal-air gap-oxide-semiconductor structure [2][3][4][5] to circumvent the influence of the gate leakage current and the device fabrication process. The contactless Zerbst method can also be used to generate wafer maps of generation lifetime and surface generation velocity by scanning a wafer with a contactless gate electrode.…”