High-temperature furnace for SiC and GaN annealing and Graphene growth
The centrotherm c.ACTIVATOR 150 high temperature furnace line has been developed for post implantation annealing of Silicon Carbide (SiC) or Gallium Nitride (GaN) devices. The Activator 150 is available in various versions as R&D and serial production furnace and offers a high process flexibility.
The unique design of the centrotherm metal-free heating allows process temperatures up to 2000 °C and shorter process cycle times. c.ACTIVATOR 150 allows a cost-effective production due to its small footprint and low cost of ownership.
- High activation rate
- Minimal surface roughness
- Temperatures up to 2000°C
- Processing of wafer sizes from 2“ to 150 mm
- Batch size 5 or 50 wafers
- Heating rate up to 100 K/min
- Annealing of SiC and GaN wafers
- Graphene growth
The hole sheet density Ns increases with annealing temperature almost linear from 1650°C all the way up to 2050°C.
The el. activation grade at room temperature increases from 0.28% to 3.7% by factor ~13 with an implanted dose of 3x1015 cm2.
3.7% el. activation at room temperature is close to the maximum obtained if all Al atoms are on SiC lattice sites.
At the same time the hole mobility decreases from 18cm2/Vs to 10cm2/Vs by factor 1.8.
The lower mobilities are probably caused by scattering on the ionized Al atoms which have energy levels ~0.22 eV above the VB.
The sheet resistance was calculated by multiplication of the Hall mobility and sheet hole concentration.
It decreases from 41000 Ohm/sq to 6000 Ohm/sq by factor 6.8.
Annealing temperatures up to 1950 °C are clearly beneficial to reduce Rs. If high carrier concentrations are more important than high mobilities, as required to achieve low contact resistances, very high annealing temperatures even above 1950 °C can be desirable.