The electrical characterisation of semiconductors

Abstract

An important aspect of the large expansion in the development and production of solid-state devices has been the demand for more sophisticated techniques for determining the electrical properties of semiconductors, especially silicon and the 111-V compounds. A very wide range of measurement techniques now exists and it is the purpose of this article to review those techniques which are in widespread use or which show promise for future application, and at a time of continuing innovation in this area, to indicate present trends and material problems which may arise in the near future. T h e emphasis of the review is on the physics of the methods: detailed discussion of results on specific materials is avoided and it is assumed that the intrinsic material properties are well known. The review is therefore concerned with the assessment of the electrical effects of impurities and defects.Routine characterisation using the resistivity, Hall coefficient and magnetoresistance effects is reviewed and methods for determining the donor and acceptor impurity concentrations from the 77 K mobility or from the temperature dependence of the free carrier density are described. Current knowledge of the Hall scattering factor is summarised. A review is given of rapid resistivity measurement by four-point probe, spreading resistance and contactless methods. Depth profiling by spreading resistance probe on bevelled structures, and by layer removal using chemical etching, anodic oxidation and ion beam etching are also considered. A major development in the last 10 years has been the use of capacitance methods for material characterisation. T h e principal C-V methods for measuring dopant profiles are compared, and the limitations are examined in detail. Capacitance and thermally stimulated current methods for studying deep traps are reviewed and the interpretation of their results is discussed. There has been increasing concern in recent years with the minority carrier diffusion length and lifetime. Measurement of these properties by photoluminescence, cathodoluminescence, and diode current collection methods is reviewed and the MOS capacitance method for lifetime measurement is also described. The review concludes with a section on optical methods in which the use of luminescence for chemical identification of electrically active impurities is emphasised and direct measurement of properties such as carrier density and epitaxial layer thicknesses is described.

Influence of twin boundary orientation on magnetoresistivity effect in free standing 3C–SiC

“…The surface morphology of the grown layers was studied with OM. The magnetoresistance measurements were performed in a Hall mobility setup [11]. A magnetic field strength of 1.7 T was applied in the experiments.…”

Dynamics of charge carrier trapping in NO2 sensors based on ZnO field-effect transistors

“…Using a thermal velocity of 10 7 cm/s [29] and N c = 10 20 cm −3 we derive an apparent cross section in the order of 10 −20 cm −2 . This small value might suggest that in order to capture a charge carrier, a repulsive barrier has to be surmounted [25]. However, the attempt-to-escape frequency may be grossly underestimated because the fitting parameters are not independent.…”

“…The data was analyzed using several models, viz. the initial rise time method [23,24], the heating rate method [25,26] and the curve fitting method by Cowell and Woods [27,28].…”

Linking structural and electronic properties of high-purity self-assembled GaSb/GaAs quantum dots

“…C-V measurements and in particular DLTS measurements [27][28][29] are the best methods to obtain detailed information about their position. Previously, there have been only two DLTS studies of the GaSb/GaAs QD system to the best of our knowledge.…”