A preponderance of critical levels for the 90-nanometer (nm) process technology node utilize 193 nm lithography. The resist systems used in this processing show a much higher sensitivity to line width slimming at the traditional electron beam energies encountered in Critical Dimension Scanning Electron Microscope (CD SEM) metrology than do previous generations of chemically amplified resists. The uncertainty that results from this undesirable interaction can consume more than the entire process control budget for advanced devices. This paper reports measurements of resist CD uniformity taken with a new CD SEM metrology technology based on ultra low voltage, that significantly reduces the impact of the electron beam on 193 nm resist systems. Over the past several months this technology has been used for 193 nm resist development studies at ARCH Chemicals. Several examples, demonstrating the effectiveness of this new technology using the Yosemite Ultra Low voltage CD SEM will be presented and contrasted against results obtained at higher voltages.