04/05/2010 Priyadharshini S. Advanced VLSI Design – Homework 4 The High-k Solution Authors: Mark T. Bohr, Robert S. Chau, Tahir Ghani, Kaizad Mistry a) Important points the authors make : 1. With new generations, the insulation material used in transistors had become too thin and could not be made any thinner. This was also leading to unnecessary power dissipation due to leakage caused by electron tunneling through the insulation layer. A material with high k (dielectric constant) could solve the problem since it would provide the same capacitance with higher thickness . 2. Hafnium- and zirconium- based dielectrics, deposited by the atomic layer deposition technique , exhibited the required stable electrical characteristics. 3. Metals were found to be the appropriate gate material  that would work well with the new insulating layer. The work function of these metals had to be modified so that the threshold voltage of the transistors was appropriate.
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