Dry etch recess of an InGaAs/InAlAs/InP HEMT like structure using a low energy high density SiCl4 plasma (ICP)

The use of an extremely low ion energy of an extremely dense plasma has been studied as a dry etching tool for InP device processing. Under these working conditions it is expected to control well the etch depth and produce minimum ion induced damage. The gate recess of an InP-based HEMT has been addressed as one of the key technological steps that requires such properties in order to achieve good device performances. InGaAs/InAlAs HEMT like structures have been grown and the recess of the InGaAs layer has been conducted with a 13 eV SiCl₄ inductively coupled plasma (ICP). DLTS measurements made on the exposed AlInAs surface after InGaAs removal indicate that the amount of induced damage is very low. These good electrical results are associated with the good morphology of the recess surface observed by AFM measurements. Both of these results are compatible with HEMT device processing