Qualification of OMVPE AlGaAs/GaAs HBT structures using nondestructive photoreflectance spectroscopy

摘要: Abstract High performance heterojunction bipolar transistor (HBT) integrated circuits are extremely dependent upon the uniformity and quality of III–V compound heteroepitaxial materials used in their fabrication. HBT requirements include need for excellent control over layer thickness, uniformity, alloy composition, intentional impurity concentration a wide range carrier concentrations. We have contactless technique photoreflectance (PR) to evaluate structures various epitaxial design correlated measured PR results with performance. was performed 1.3–2.0 eV which is ideally suited probing AlGaAs/GaAs structures. The resulting signals gave information about gap energy material probed (and thus its composition) built-in DC electric fields within layers. Measurement spectral observed Franz-Keldysh oscillation extrema near GaAs AlGaAs edges, were determine field collector emitter regions. These good agreement distribution calculations obtained by solving Poisson continuity equations an structure. Run-to-run from multi-wafer OMVPE reactor characteristics.