استفاده از روش ، همه کاره، با فرکانس پایین و خصوصیات مستقیم سر و صدا مقاوم برای مواد / فرایند کنترل کیفیت با استفاده از دستگاه 4 ترمینال متقابل شکل

Low frequency (LF) noise measurement is a very sensitive tool for device quality and reliability monitoring. Despite of its potential interest, there are up to now relatively few LF noise studies combined and compared to standard reliability/quality analysis. One of the reasons is the difficulty to implement LF noise measurement on automatic wafer level testing. In this paper we promote a method using cross shaped 4 terminal devices (Hall crosses). The implementation of this method and its advantages over conventional noise measurement methods are described. This method, compatible with on-wafer probe testing, is of particular interest for material/processes quality control purposes especially for less mature material such as AlGaN/GaN Heterostructures.

Low frequency noise (or "excess noise") is in principle very efficient and sensitive for revealing electrically active defects in semiconductor devices. LF noise is also affected by degradation mechanism and process quality. It has been observed, in some cases,that devices showing higher excess noise are less reliable and have shorter lifetime [1, 2]. Therefore, it would be very tempting to routinely use noise measurements for quality control as well as for characterization of aging processes and reliability in semiconductor devices.However, such a technique is not widely used in a production environment, partly due to the difficulty of performing on-wafer noise measurements [3]. Indeed,fluctuations known as "noise" are small as compared to the common-mode potential drop in a biased device.

In this paper we have presented a low frequency noise measurement method for Material/Process Quality/Reliability purposes using 4 terminal devices.This alternative to more complex standard methods can be of great help for developing systematic LF noise approach combined with reliability (accelerated aging) or quality control and get clear correlations. The method is also well suited for LF noise spectroscopy [5] since the bridge formed by the cross remains balanced when varying the temperature or the gate/substrate voltage.