Evaluating Nanoscale Ultra-thin Metal Films By Means Of Lateral Photovoltaic Effect In Metal-semiconductor Structure

Nanoscale metal-semiconductor(MS)structure materials occupy an important position in semiconductor and microelectronic field due to its abundant physical phenomena and effects.The thickness of metal films is a critical factor in determining characteristics of MS devices.How to detect or evaluate the metal thickness is always a key issue for realizing high performance MS devices.In this work,we propose a direct surface detection by use of the lateral photovoltaic effect(LPE)in MS structure,which can not only measure nanoscale thickness,but also detect the fluctuation of metal films.This method is based on the fact that the output of lateral photovoltaic voltage(LPV)is closely linked with the metal thickness at the laser spot.We believe this laser-based contact-free detection is a useful supplement to the traditional methods,such as AFM,SEM,TEM or step profiler.This is because these traditional methods are always incapable of directly detecting ultra-thin metal films in MS structure materials.In the second part,we report the work progress of light regulated Hall effect.From the 19 th century the research and discussion about Hall effect have never stoppped.The measurement of Hall coefficient and conductivity has been described as one of the main methods for studying semiconductor materials.We choose P type silicon as the research sample and test its Hall coefficient.We shoot a laser bean on the sample and detect the hall voltage,hall resistance and other data,along with the change of laser location.Experiment results show that the photon-generated-carrier certainly has influence on hall effect,How to realize the control by light is the key point of further work.