Germanium for VCSEL Applications

Main characteristics of Germanium for VCSELs

No dislocations

Umicore Germanium has 0 EPD (etch pitch density), which results in a better yield and long term device reliability. The burn-in of final devices may be reduced.

Germanium compared to Silicon and GaAs

Property

Silicon

GaAs

Germanium

Crystal Structure Diamond Zincblende Diamond Si and Ge are elemental semiconductors with similar large (12") diameter 0 EPD* cyrstal processes
Density (g/cm³) 2.33 5.32 5.33
Lattice constant (Å) 5.430 5.653 5.658 Ge and GaAs are lattice matched
Bandgap energy at 300K (eV) 1.12 1.42 0.66
Electron mobility (cm²/V-s) 1350 8500 3900 Ge has both high electron and hole mobility
Hole mobility (cm²/V-s) 480 400 1900
Melting point (°C) 1415 1238 937
Thermal expansion (1/°C) 2.6 10-6 5.7 10-6 5.9 10-6 Ge and GaAs have similar thermal expansion
Thermal conductivity (W/cm°C) 1.3 0.55 0.55
Fracture thoughness (MPa.m1/2) 0.8 0.31 0.66 - 0.72 Ge is twice as tough as GaAs

* EPD: Etch pitch density, dislocation density

×

      Umicore uses certain monitoring and tracking technologies such as cookies. These technologies are used in order to maintain, provide and improve our services on an ongoing basis, and in order to provide our web visitors with a better experience.

      By clicking on the "Accept all" button you agree to the use of these cookies while using the website. For further information regarding how we use cookies and other tracking technologies, please see section 11 of our website privacy notice

          Necessary cookies are essential and help you navigate our website. This helps to support security and basic functionality and are necessary for the proper operation of our website, so if you block these cookies we cannot guarantee your use or the security during your visit.

          Cookies that help us to understand the behaviour of users of our website. This allows us to continuously improve our website to provide the best information in support of our project aims. These cookies also help us understand the effectiveness of our website. For instance these cookies tell us which pages visitors go to most often and if they get error messages from web pages.

          Cookies that deliver content to you based on your interests, which are assumed from your browsing history. Most Targeting Cookies track users via their IP address and, thus, may collect some Personal Data. Personal Data collected by Targeting Cookies may be shared with third parties, such as advertisers.