Avalanche multiplication noise characteristics in thin GaAs p(+)-i-n(+) diodes

Avalanche noise measurements have been performed on a range of homojunction GaAs p( )-i-n( ) and n( )-i-p ( ) diodes with "i" region widths, omicron from 2.61 to 0.05 mum. The results show that for omicron 1 mum the dependence of excess noise factor F on multiplication does not follow the well-established continuous noise theory of McIntyre [1966]. Instead, a decreasing noise factor is observed as omicron decreases for a constant multiplication. This reduction in F occurs for both electron and hole initiated multiplication in the thinner omicron structures even though the ionization coefficient ratio is close to unity. The dead-space, the minimum distance a carrier must travel to gain the ionization threshold energy, becomes increasingly important in these thinner structures and largely accounts for the reduction in noise