Direct channel length determination of sub-100 nm MOS devices using scanning capacitance microscopy

• Published in: 1998 Symposium on VLSI Technology Digest of Technical Papers (Cat. No.98CH36216) pp. 138 - 139
• Main Authors: Kleiman, R.N., O'Malley, M.L., Baumann, F.H., Garno, J.P., Timp, W.G., Timp, G.L.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 1998
• Subjects: Capacitance; Doping; Electrodes; Geometry; Microscopy; MOS devices; MOSFET circuits; P-n junctions; Spatial resolution; Voltage
• ISBN: 0780347706; 9780780347700
• DOI: 10.1109/VLSIT.1998.689232

As MOSFET channel lengths are scaled to below 100 nm, the determination of the effective channel length, L/sub 0/ becomes increasingly important. We have studied cross-sectioned MOSFETs with gate lengths down to 90 nm using scanning capacitance microscopy (SCM), and show the first images of these state-of-the-art devices. Using a device simulator we have quantitatively established the relation between L/sub 0/ and the SCM response in the channel region, allowing us to determine L/sub 0/ from the SCM measurements. We have explored the ultimate resolution attainable using this technique; experimentally, using very sharp probe tips and with numerical simulations.