Are there technical documents about microprocessor design by Jim Keller?
Try searching for James B. Keller or JB Keller or J. Keller. I think you'll find a number of publications which list him as an author. For example, US 8775757, US 8392658 patents, some more patents listed here

Also "Measuring VAX 8800 performance with a histogram hardware monitor", "Internal architecture of Alpha 21164 microprocessor", "A 600 MHz superscalar RISC microprocessor with out-of-order execution" IEEE 

Interestingly, perhaps, he's apparently married to the sister of (in)famous Canadian clinical psychologist and author Jordan Peterson.