Formation and Characterization of the High Precision Nanoscale Thin Film Resistors on Radio Frequency Application

摘要

In this paper, a high-precision tantalum nitride thin film resistor was fabricated using a novel plasmaion etching method. Sheet resistance and x-ray spectra confirmed that the composition and crystallinelattice of the tantalum nitride film varied upon different nitrogen flow ratios of sputtering. To obtain agood performance, we proposed a novel two-step etching process for the fabrication of tantalum nitridethin film resistor, that is, firstly etched using a Cl2 plasma for the purpose of sharp profile and fastetching rate, and followed by a Cl2/O2 gas mixture plasma to get a better etching selectivity. Thetemperature coefficient of resistance of the tantalum nitride thin film resistor showed that thetemperature-related disturbance increased upon increasing the nitrogen composition of device. Thetemperature-related stability of the thin film resistor was further improved by post-deposited ammoniaplasma treatment. The flicker noise, measured at frequency from 1 to 100k Hz, also showed that thecurrent noise depended on the nitrogen composition of the thin film resistor. The characteristic of radiofrequency dependent resistance, which was measured ranging from 1 to 20 GHz and extracted by two- ported S parameter and telegrapher transmission line model, also showed that the stability oftantalum nitride thin film resistor decreased upon increasing the nitrogen composition.