THE CVD OF GERMANIUM

Germanium was the semiconductor material used in the development of the transistor in the early 1950s. However, it exhibits high junction leakage current due to its narrow bandgap and is now largely replaced by silicon. It is a brittle metalloid element with semiconductor characteristics. The properties of germanium are summarized in Table 8.3.1 lP l 

Electrical resistivity, flcm 4-40 Bandgap at 300K (eV) 0.66 Drift Mobility 

Hardness, Kg/mm2 780 Flexural strength 13000psi Young s modulus 14.9 Mpsi Poisson s ratio 0.28 

Single crystal germanium can be deposited by the hydrogen reduction of the chloride at 600-900°C as follows ] 

It is now produced mostly from the decomposition of germane, usually at atmospheric pressure and at temperatures ranging from 600 to 900°C as follows  

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