Impact of in situ atomic layer deposition TiN/high-κ stack onto In0.53Ga0.47As MOSCAPs on 300 mm Si substrate

Abstract

We investigated the impact of an in situ atomic-layer-deposition (ALD) TiN/high-κ dielectric onto In0.53Ga0.47As 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 ZrOxNy 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 In0.53Ga0.47As 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.