The chip design consists of a simple 10×10 array of transistors that Zeloof was able to lay out in Photoshop. As before, the entire process took place in his “garage fab” using impure chemicals, homemade equipment and without a clean room.
The Z2 is leaps and bounds better than the Z1. Switching to a polysilicon gate process reduced power consumption significantly, but without pure chemicals and in the absence of a clean room, yields are low.
“I’ve made 15 chips (1,500 transistors) and know there’s at least one completely functional chip and at least two “mostly functional”, meaning ~80 percent of the transistors work instead of 100 percent,” Zeloof said.
The most common defect, he said, is a drain or source shorted to the bulk silicon channel. With the Z1, the biggest issue was a leaky or shorted gate.
Jesus: Hey, Dad? God: Yes, Son? Jesus: Western civilization followed me home. Can I keep it? God: Certainly not! And put it down this minute--you don't know where it's been! Tom Robbins in Another Roadside Attraction