A Proposed Hydrogenation/Nitridization Passivation Mechanism for GaAs and Other III–V Semiconductor Devices, Including InGaAs Long Wavelength Photodetectors

A surface passivation method for , with possible extensions to and , is proposed. For , a correlation between recent device work (on solar cells, field effect transistors, MOS devices, and photodiodes) and the experimental Ga‐As‐O phase diagram provides strong evidence of the role of elemental surface or interface arsenic or arsenic oxide in device performance degradation. On this basis, a hydrogenation/nitridization passivation technique is proposed. The reactions to remove surface As and are The surfaces may be plasma coated in the same chamber with a wide bandgap nitride ( e.g. , ) for passivation and to tie up any elemental Ga. The hydrogenation and nitridization steps may be simultaneous if an ammonia plasma is used. A final layer for long‐term surface protection is recommended. Recent experimental data on surface treatments support this passivation mechanism. The extension to (for long wavelength optical detectors) is by thermochemical calculations supported by recent parallel measurements of the In‐Ga‐As‐O phase diagram. Note the conductive indium oxide must also be removed, as by the reaction