Interface traps in 28 nm node field effect transistors detected by capacitance transient spectroscopy

The energy distribution of the interface trap density for high-k metal gate field effect transistors, fabricated in the standard 28 nm node technology and subjected to various fabrication processes was obtained using the capacitance transient spectroscopy (CTS) method. The CTS results show a nice correspondence with those obtained by the characterization methods routinely used in semiconductor industry, but contain more information. Strong influence of the infrared illumination on the results of the CTS measurements was detected at temperatures T<200K. Therefore, a proper shielding from infrared irradiation is required during transient spectroscopy measurements at low temperatures.