InGaAs/InAlAs heterostructure is realized on GaAs substrate. This GaAs-based metamorphic high electron mobility transistor (mHEMT) heterostructure can reduce the stress at the interface between heterostructure and GaAs through the gradual change of In composition. Such a mHEMT structure can provide device performance that is superior to GaAs-based pHEMT and close to InP-based HEMT, and can be integrated with GaAs-based circuits. PAM-XIAMEN can offer 4″GaAs mHEMT epi wafer (GaAs MBE epiwafer), please see below typical structures:
1. Specifications of GaAs MHEMT Epi Wafer
No.1 GaAs Epi Wafer for Metamorphic High Electron Mobility Transistor
| Epi layer | Material | Mole of In | Thickness(Å) | Dopant | Concentration |
| 7 | InGaAs cap | 0.53 | 200 | Si | 6.0E18 cm-3 |
| 6 | InAlAs barrier | 0.52 | – | – | – |
| 5 | Planar doping | – | – | Si | 6.0e12 cm-2 |
| 4 | InAlAs spacer | 0.52 | 45 | – | – |
| 3 | InGaAs channel | 0.53 | – | – | – |
| 2 | InAlAs buffer | 0.52 | – | – | – |
| 1 | InAlAs M-buffer | – | – | ||
| 4 inch S.I GaAs susbtrate, Mobility: 9230 cm2/V·s, Ns: 3.26E12 cm-2 | |||||
No.2 GaAs mHEMT Wafer
N+ In0.53Ga0.47As 20nm (n=1×10^19 cm^-3)
N+ InP etch stopper 5nm (n=5×10^18 cm^-3)
i- In0.52Al0.48As Schottky barrier 10nm
Si-delta-doping (n=6×10^12 cm^-2)
i- In0.52Al0.48As spacer 4nm
i-In0.53Ga0.47As channel 15nm
In0.52Al0.48As buffer 300nm
metamorphic buffer 300nm (linearly graded from substrate to In0.53Ga0.47As)
S.I. GaAs substrate
Moreover, we can supply (p)HEMT epitaxial wafers based on GaAs or InP substrate. Additional wafer structures, please refer to
GaAs HEMT epi wafer: https://www.powerwaywafer.com/GaAs-HEMT-epi-wafer.html
GaAs pHEMT epi wafer: https://www.powerwaywafer.com/gaas-phemt-epi-wafer.html
InP HEMT epi wafer: https://www.powerwaywafer.com/inp-hemt-epi-wafer.html
2. About mHEMT Device
MHEMT devices are developed from HEMT devices. From the structure of material layer, mHEMT device is to move InP based InAlAs/InGaAs heterostructures onto GaAs substrate, so that it not only has the advantages of high electron concentration, high mobility and high saturation speed of InP HEMT, but also gets rid of the disadvantages of high cost of InP substrate, low mechanical strength and friability when processing. It is the latest development direction of HEMT devices, and it has strong appeal in low noise high power applications.
