InP based

InP in-situ monitoring and mapping of InP films from Epi to Etch.

Applications Metrology solutions Related products

InP based materials exhibit higher electron mobility and higher frequency response compared to GaAs. This makes InP HBTs a good candidate for next generation trans-impedance amplifiers in optical fiber communications and for 6G applications. Moreover, since InP HBT’s base bandgap energy is much lower than that of GaAs HBTs, the InP based device’s turn-on voltage and related power consumption are significantly lower. However, the high-yield MOCVD growth of device grade quaternary InGaAsP and InGaAlAs structures precisely lattice matched to InP substrates is rather challenging, especially on larger wafers. Here, in-situ process control based on accurate high temperature quaternary nk data can be key.

  • Reflectance at 3 wavelengths for monitoring of growth rate and morphology (EpiTT and EpiCurve®TT product families)

  • Wafer surface temperature (EpiTT and EpiCurve® TT product families)

  • Wafer curvature for strain management of layer stacks (EpiCurve® TT)

Name Size
EpiX data sheet 3.32 MB
Talk - Plasma etching of InP-based lasers at APCM_2025 2.51 MB
Newsletter January 2020 - MBE_Facet & InP-QCLs 465.08 KB
Talk - AlGaInAs MQWs growth on InP/SiO2/Si substrates 2.75 MB
Talk - How to enhance epitaxy process performance by in-situ data 3.4 MB
Talk - MOCVD of InGaAsP/InP and InGaAlAs/InP based device structures 1.31 MB
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Metrology solutions

The respective composition range (x=0…1) covers the reference (PL) wavelength range 0.92–1.65 µm for InGaAsP and 0.85–1.65 µm for InGaAlAs. The three lines for each material system give the 633 nm refractive index at three wafer temperatures.
In-situ data obtained by EpiCurve®TT: The quaternary/ternary layers (steps 17–29) are lattice matched to InP (step 15) as can be seen from the unchanged wafer curvature (green line). Hence, the measured 633 nm reflectance data (blue line) of an InP/InGaAsP device tructure can be exactly fitted (red line) yielding all compositions x and all growth rates. The –3 K reduction in wafer temperature due to the changed As/P ratio is a real effect.

LayTec’s EpiCurve® TT metrology system allows to monitor all crucial parameters needed for control ling the epitaxial growth of InP-based thin film. With LayTec’s  emissivity-corrected pyrometry the true wafer temperature can be controlled precisely, whilst the actual layer growth can be monitored by EpiTT’s three dedicated reflectance wavelengths. At the same time wafer bowing and strain management can be addressed by the deflectometry in LayTec’s EpiCurve® TT. All these methods are complemented by the comprehensive EpiNet software which allows for detailed and precise quantitative analysis of the measurement results by employing our extensive high-temperature nk database.

Example: Control of device related InGaAsP and InGaAlAs film growth on InP: When lattice matched growth is validated by in-situ wafer bow sensing, both quaternary material systems can be treated as an effective quasi-ternary mixture: (InGaAs)x(InP)1-x and (InGaAs)x(AlGaAs)1-x , respectively.

Contact

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infolaytec.de +49 30 8900550