A road map for optical lithography
What international forum manages lithography targets and requirements for the industry? From what regions of the world
is this forum sponsored? What is the goal of this forum? What is a node? What node are we at currently and where are we
headed over the next 10-15 years?
What is CDmin, why is it important, and what parameters affect its value? Over what range of values have these
parameters changed over the past 20 years and what are the prospects for changing them further?
What is the highest resolution achieved with optical lithography in this paper and how was it done? Give an example of
how we might reach the 23-nm node and how we may reach sub-23 nm node?
Paper #2. Lithography and other patterning techniques for future electronics. Read the paper and answer the following
questions (25 points total).
Describe the driving forces behind improvements in lithography / patterning, touching upon the relation to the IC industry and scaling effects in particular. Review the history of semiconductor IC patterning since the 1960s, touching upon printing techniques, optics, illumination sources and mask making techniques.
What determines lithographic resolution in proximity printing?
What type of diffraction is important?
Why is lowering wavelength difficult?
What is the drawback of going to x-rays?
What wavelength is the industry holding at now and what developments have enabled IC production at lower nodes?
What variant technology is the favorite to supplant optical lithography?
Why is it better than the conventional variant? What are some of its characteristics? Define mechanical patterning, chemical patterning and mixed patterning.
What are the advantages and disadvantages of non-radiation-based patterning? Give an example of mechanical patterning and an example of chemical patterning. Very briefly describe each example.