Minimizing Pattern Dependency in Millisecond Annealing

Millisecond annealing is a key enabling technology for creating the ultra-shallow junctions of the 65nm node and beyond. The very short thermal diffusion distances inherent in millisecond annealing exacerbate larger scale pattern density differences and can result in corresponding differences in annealing temperatures. This paper considers the three different methods of achieving millisecond annealing times and the various ways that pattern effects can be minimized in each case. These include opaque coatings, dummification and careful selection of the wavelength, incidence angle and polarization of the radiation used for annealing. Each method has its own set of advantages and disadvantages and these are enumerated. The article concludes with a short comparison of the results obtained with three commercially available, millisecond annealing systems.