IC Mask Design: Essential Layout Techniques

Make a copy of the preceding schematic to place in front of you as you read along with this Case Study. Read through the Study once for general perspective. Read it again for analysis and better understanding. Read it again and again to increase your level of understanding and your internalization of these good practices.
Enjoy.
Bill is a mask designer. He's been with the Can't Tell Corporation for five years generating CMOS input/output cell layouts. That's all he's been doing-just I/O cells for five years.
He is rather bored with generating I/O cells all the time. His manager refuses to put him on anything he finds interesting, so he begins to look through the corporate job postings. He sees that there is an opening for a mask designer in a new department being formed at the same company site, but three buildings away.
Bill wanders down to Building Four and learns more about the job. He realizes the new position will be very challenging for him. He applies for the job, goes through the interview process, and eventually is transferred into this new department.
Because the department is new, Bill is their first mask designer. The circuit designers are very pleased that they finally have a mask designer to work with. Up until now they have been doing their own layout and have not really been enjoying the work. Consequently, they are keen to get someone who knows how to run the tools, someone who...