Hot-point probe measurements of N-type and P-type ZnO films

Abstract

Purpose

This paper aims to develop a low-cost hot-point which can facilitate the conductivity type of N-type and P-type zinc oxide (ZnO) films. In this study, a diode was made out of the N-type and P-type ZnO films, and current-voltage (I-V) characteristic measurements were conducted.

Design/methodology/approach

A low-cost hot-point probe consists of a soldering iron station, digital multimeter and a pair of probes. The setup is adopted to identify N-type and P-type ZnO films. In particular, P-type films have been deployed for the first time.

Findings

Hot-point probe setup has been successfully developed. Measurements of N-type films give a positive voltage reading, whereas P-type films give a negative voltage reading. The measured voltage dominates at 1 per cent for N-type Ga and at 15 per cent for P-type Na. I-V characteristics of the fabricated diode showed a similar trend to the conventional diode.

Research limitations/implications

N-type has been often attempted. However, P-type has rarely been attempted because of the self-compensation effect in ZnO. There is a need to verify the conductivity type of ZnO films, especially P-type, as P-type films are not stable. The hot-point probe setup serves as a quick means to verify P-type ZnO films.

Originality/value

To the best of the authors’ understanding, this verification tool was developed and deployed to verify the N-type and P-type ZnO films. The P-type films are coated on top of the N-type films for diode I-V measurements.

Citation

Au, B.W.-C., Chan, K.-Y., Sin, Y.-K. and Ng, Z.-N. (2017), "Hot-point probe measurements of N-type and P-type ZnO films", Microelectronics International, Vol. 34 No. 1, pp. 30-34. https://doi.org/10.1108/MI-08-2015-0067