Low-K CMP process control by using interpolation method
For ILD CMP process, accurate polish time control is required to obtain expected film thickness. Comparisons between conventional SiO2 CMP process and low-k CMP process were studied and realized polishing time for low-k material can not be determined by only removal rate due to the existence of incubation time at first stage. Interpolation method was evaluated to determine polishing time for low-k CMP process. Correction of this incubation time was performed by using interpolation method and promising results were obtained.
Multiple objective APC application for an oxide CMP process in a high volume production environment
Presents three independent run-to-run APC controllers for the chemical-mechanical polishing (CMP). The controllers are applied to oxide polish processes in AMD's Fab30 to improve (a) the lot-to-lot variation, (b) to reduce the wafer-to-wafer variation and (c) to increase the wafer uniformity of the post-polish oxide thickness. Since different products and layers are processed on the same tools a method was introduced to compensate device and layer dependencies. The control algorithms were extended to a bi-layered polish process. Significant improvement was achieved for the individual controllers applied in the high volume production environment of Fab30 under the condition of a permanently changing product mix.
Augusta Klumpke: pioneering female neurologist.
The latter part of the 19th century was an exciting period when women at last were succeeding in their battle to obtain their medical training and qualifications to practice in the UK, continental Europe and in the USA. Moreover, and perhaps not surprisingly, many of these determined and doughty pioneers showed themselves to be exceptionally able in their chosen specialities. Perhaps the best example of this was Augusta Klumpke (Figure 1), who became an outstanding neurologist in Paris. This year marks the 150th anniversary of her birth.