The UK government has asked your wafer manufacturing company to fabricate a single-batch of 10,000 highly specialised

Fantastic news! We've Found the answer you've been seeking!

Question:

The UK government has asked your wafer manufacturing company to fabricate a single-batch of 10,000 highly specialised chips. The amount they will pay per chip is so large that you can use any fabrication technologies during manufacture, even ones only in the testing phase. Your task is to design the fabrication process from start to finish, choosing the most appropriate techniques for each step. However the specifications for the chips are very demanding. These specifications are

 The minimum feature size on each chip is 7 nm, so conventional optical lithography (even using tricks such as phase shift masks) will not be good enough. You must choose another form of lithography.

 All features on the chips should be made as small as possible, so each fabrication step you use should be optimised to achieve this.

 The chips contain MOSFETs that require charge carriers to have particularly high mobilities to operate successfully, so each fabrication step you use should be also optimised to achieve this.

(a) State what processes you will use for each stage of fabrication (one for each), including wafer growth; patterning of features; etching; creation of source and drain contacts, interconnects, layers of materials etc.; and any other stages you think are relevant. For each process, explain why you chose the technology you did, and why it is better than the alternative technologies available to you.

(b) Explain the various ways in which the mobility of the MOSFETs can be maximised, which fabrication steps will be important for achieving high mobility and how you have integrated any of these steps into your overall fabrication process

(c) Describe the main difficulties you envisage, including fabrication problems, in successfully manufacturing 10,000 devices with such small components.