InPUntergrund

InPUntergrund refers to indium phosphide (InP) substrates used as the foundational crystalline platform for epitaxial growth in III–V semiconductor devices. InPUntergrund wafers are typically single-crystal ingots sliced into wafers and finished to epi-ready quality. Indium phosphide is chosen for its direct bandgap and high electron mobility, making it suitable for near-infrared optoelectronics and high-speed electronics. Wafers are commonly produced in diameters of about 2 to 4 inches (50 to 100 millimeters) with thicknesses around 300 to 500 micrometers, and surface finishes optimized for epitaxy.

Common substrate orientations include standard crystallographic planes such as (001) and (111), often with a slight miscut to control step-flow growth. Substrates may be undoped or lightly doped to achieve desired resistivity, and they can be semi-insulating or n- or p-type depending on the device requirements. Surface preparation involves chemical cleaning, oxide desorption, and polishing to epi-ready states.

InPUntergrund serves as the platform for deposition of InP-based and related alloys, such as InGaAs, InAlAs, and InGaAsP, by epitaxial techniques including molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). These layered structures form lasers, modulators, photodetectors, and integrated photonic circuits used in telecommunications and photonics.

Availability and lead times depend on diameter, resistivity, and surface quality, with multiple suppliers offering standard and custom specifications.