We report high performance, dry etched In<inf>0.53</inf>Ga<inf>0.47</inf>As vertical nanowire and vertical nanosheet devices, fabricated using a VLSI compatible process flow. Scaling the effective-oxide-thickness in combination with (NH4)2S channel treatment and forming gas anneal improves the device performance, in terms of Q (Gm/SS), by over 55%. At V<inf>DS</inf> = 0.5V, the devices exhibit a minimum SS = 63mV/dec, I<inf>on</inf> = 397μA/μm at Ioff = 100nA/μm, peak Gm = 1.6mS/μm and maximum Q = 21. These values are the best reported in literature for vertical IIIV devices. A reliability analysis puts these vertical MOSFETs in line with other IIIV devices with similar gate stack, indicating that the process flow does not introduce additional interface defects.