This paper reviews two types of sensor wafers that fit into the niche of spatially resolved in situ plasma diagnostics. The effect of both the incident power and the backside He flow on wafer surface temperature map was studied with the temperature sensor wafer. It was shown that the differential information related to the ion flux density distribution can be estimated in the case of two comparable recipe settings in a complementary way. Another sensor wafer is designed to measure the distribution of displacement current passing through the wafer. Calibrated at 13.56 MHz, it is capable of working in a wider range of source frequencies that has successfully been demonstrated in CCP reactors. It was found that the particular type of plasma reactor and the process chemistry selected can impact the level of correlation between the sensor and the blanket etch rate uniformity data. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.010201jes]