Minority Carrier Lifetime Measurement Based on Low Frequency Fluctuation
- PDF / 288,364 Bytes
- 11 Pages / 595 x 842 pts (A4) Page_size
- 63 Downloads / 225 Views
1195-B09-04
Minority Carrier Lifetime Measurement Based on Low Frequency Fluctuation Ke Lin1, Huang Sha2, Chua Soo Jin 1,2, Lai Szu Cheng1, Surani Bin Dolmanan1 1
Institute of Materials Research and Engineering, Agency of Science Technology Agency, 3 Research Link, Singapore 117602 2
Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576
ABSTRACT We present a novel, simple, and accurate approach based on low frequency voltage fluctuations to determine the averaged carrier lifetime in semiconductor materials and devices. This technique serves to address the limitations faced by existing techniques that use light as the excitation source for lifetime measurement. In this paper, the minority carrier lifetime is inferred from the 1/f low frequency noise profile exhibited by the device during low current operation. The current dependence of the power spectral density and its relation to minority carrier lifetime is modeled and derived directly giving a current dependent carrier lifetime. This technique is solely based on the electrical noise and no light source is required for excitation. The low frequency noise can be easily acquired without significant distortion via a signal analyzer as long as there is a sufficiently good Ohmic contact between the probe and the device under test, and that the device is sufficiently shielded from the influence of EMI. This technique has lower crosstalk, fewer fitting parameters, is low cost and allows the lifetime to be extracted directly from data collected at lower frequencies. These characteristics make our method useful in encapsulated devices, applicable on wafers and devices in production-lines and where light excitation is difficult to access the active material. INTRODUCTION In semiconductor applications, minority carrier lifetime is the average time taken for an excess minority carrier to recombine. It is a significant parameter governing the performance of semiconductor devices. The minority carrier lifetime can determine factors such as switching speeds of diode and transistor devices, and energy conversion efficiency of solar cells and power output efficiency of light emitting diodes (LEDs). Therefore, to characterize the performance and quality of a semiconductor device, an accurate measurement of the minority carrier lifetime and its related parameters is typically desired. Currently, there have been proposed a number of different methods of determining minority carrier lifetime. For example, estimating minority carrier lifetime based on observing decay signal profiles from reflected microwaves. Measuring composition characteristics of a test device with an optical method for extracting minority carrier lifetime. Using reflected radiofrequency signals, infra-red emissions or light-induced capacitance etc. to estimate minority carrier lifetime. In these methods, e.g.
radiofrequency signals and infra-red emission are used for observing the recombination (decaying) profiles. However, optical light s
Data Loading...
