Study Of Electrical Properties Of Czochralski Silicon By Means Of Hall Effect Measurement

Hall effect measurement is an important means for characterization of semiconductor, which can be used to measure the conduction type, carrier concentration, mobility and so on. Therefore, it is extensively employed in research and industry. In this thesis, Hall effect measurement has been used as the primary means to investigate the temperature-dependence of electron mobility in heavily doped n-type Czochralski (CZ) silicon, the appropriateness of Klaassen model for n-type compensated CZ silicon and the electrical activity of nitrogen injected by high temperature RTP in N2ambient into CZ silicon. The primary results are listed as follows.(1) The temperature dependences of resistivity, carrier concentration and carrier mobility for heavily phosphorus-doped and heavily boron-doped CZ silicon wafers have been investigated. It is found that the conduction mechanism shifts gradually from conduction (or valence) band conduction to impurity band conduction with decreasing temperature, and the shifting temperature range becomes higher as the doping concentration increases. The temperature dependences of resistivity, carrier concentration and carrier mobility are modulated by the forementioned conduction mechanism shift.(2) The dependence of electron mobilities in n-type phosphorus-boron compensated Czochralski (CZ) silicon crystals on phosphorus concentration has been investigated by means of Hall effect measurement and second ion mass spectroscopy. Through comparison between the measured electron mobility values and the calculated electron mobility values based on Klaassen model, it is found that Klaassen model is appropriate for calculation of electron mobility in compensated CZ silicon with a doping level of the order of10/18cm-3, but it overestimates the electron mobility in compensated CZ silicon with a doping level of the order of10/17cm-3. It is believed that klaassen model has not substantially taken into account the weakening effect of compensation on the screening of ionized impurity by free carriers in the case of light-doping. According to the experimental result, Klaassen model has been modified so that its calculated electron mobility values accord well with the measured ones.(3) The electrical activity of nitrogen injected by high temperature RTP in N2ambient into CZ silicon has been investigated. A portion of the nitrogen atoms injected by a RTP treatment of1250℃/60s exist electrically actively in substitutional form, which reaches the saturation concentration of2X10/13cm after3RTP treatments. The above RTP treated samples then underwent a650℃annealing and formed nitrogen-oxygen complexes, which indicates that a portion of the nitrogen atoms injected by RTP treatment exist in the electrically inactive form of nitrogen panir...