Characterization of GaAs layers grown directly on Si substrates by metalorganic chemical vapor deposition

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Abstract
The electrical and structural properties of GaAs layers grown directly by metalorganic chemical vapor deposition on Si substrates oriented 2° off (100) toward [011] are reported. The uniformity of minority‐carrier lifetime in the 2 in.‐ diam heteroepitaxial wafers is comparable to that in bulk GaAs of the same doping density (2×1016 cm−3). Selective etching of the GaAs layer reveals an etch pit density of ∼108 cm−2, consistent with plan view transmission electron microscopy which shows a defect density of ∼108 cm−2. Rapid annealing at 900 °C for 10 s does not significantly alter the heterointerface abruptness, and at the same time the crystalline quality of the GaAs improves slightly. The deep level concentration in the as‐grown layer is ∼1013 cm−3 as determined by capacitance spectroscopy. Finally, the activation characteristics of low dose Si implants (3×1012 cm−2 at 60 keV) are similar to those in high quality bulk GaAs.