Impact of in situ atomic layer deposition TiN/high-κ stack onto In_0.53Ga_0.47As MOSCAPs on 300 mm Si substrate

We investigated the impact of an in situ atomic-layer-deposition (ALD) TiN/high-κ dielectric onto In_0.53Ga_0.47As metal-oxide-semiconductor capacitors (MOSCAPs) on a 300-mm (001) Si substrate. We found that an in situ ALD TiN/ZrO₂ MOSCAP shows an improved hysteresis (36% reduction) compared to ex situ ALD TiN/ZrO₂ MOSCAP in a capacitance-voltage (CV) measurement at 1 MHz. X-ray photoelectron spectroscopy (XPS) shows the formation of the ZrO_xN_y composition for the ex situ process which is affected by the increased hysteresis in the CV characteristics. In addition, the flat-band voltage (V _FB) has shifted the forward direction for the in situ process device which is evidence of the decreasing oxygen vacancy (V _O) in the high-κ layer through the in situ process in an ALD chamber. In order to confirm the concentration change of the oxygen vacancy, the ΔV _th degradation of the TiN/ZrO₂ with an In_0.53Ga_0.47As MOSCAP under constant voltage stress (CVS) was carried out. It turns out that the in situ process has a lower V _th (63 mV) than the ex situ process at 1000 s stress. Based on the results, interface traps in between the TiN metal gate and high-κ are other defect sources which need to be considered in order to improve future III-V MOSFETs.