A New CD Measurement Method Linked with the Electrical Properties of Devices
This paper describes a new measurement method of a CD-SEM with nanometer-level precision and good correlation with electrical characteristics for an actual device of ultra-large-scale integration (ULSI). With the decrease in feature size, the pattern to be measured tends to become a curved shape. In order to measure such a pattern within measurement precision on the order of 5 nm, two-dimensional measurement is effective. Here we report a new measurement algorithm featuring that the critical dimension is derived from the value of the area of a measurement pattern. We apply this measurement method to actual device of 64-Mbit DRAM and confirm the reproducibility of 3.6 nm for the gate linewidth measurement, and that of 5.6 nm for the hole diameter measurement. Furthermore, we verify that the measurement values of the gate linewidth have a strong correlation with the threshold voltage and those of the hole diameter also have a strong correlation with the contact resistance, respectively. key words: CD SEM, metrology, curved structure, electrical
Analysis Of Linewidth Measurement Techniques Using The Low Voltage SEM
Linewidth measurement using the scanning electron microscope is not well understood. The basic intent is to measure the size of a structure from the secondary and backscattered electron signal generated by that structure1-6. Thus, an accurate measurement requires an understanding of how the profile and critical dimension of the line being measured relate to the electron signal. The complicating factor is that different features generate different signals and that surroundings often influence the detected signal from a given feature.
The Invariance of the Vacuum is the Invariance of the World
The following theorem is demonstrated: If the vacuum is invariant under the group generated by the space integral of the time component of a local vector current, then the Hamiltonian is invariant also. A similar theorem holds for the group generated by the space integral of a space component of a local axial-vector current.