Devlog #11

Since the last devlog, you can draw your own 2D devices, not just stack layers in a line.

You draw rectangles of silicon and oxide, paint doping onto them, and place metal contacts along the edges. The simulator builds a grid that fits your drawing and solves it. Before it solves, it checks for mistakes and tells you what’s wrong in plain words: a piece of silicon with no contact touching it, a gate sitting right on silicon, or a shape too small for the grid to see. To make sure drawing works, I redrew the MOS capacitor and the transistor I already had and checked that they give the same answers. The capacitor matched almost exactly and the transistor was within about 1%.

Testing it in a real browser caught two bugs. One made every solve hang forever. The other made the picture of the device grow every time it redrew on high resolution screens. Both seem to be fixed now but I’ll be on the lookout for similar bugs.

Then I tried something new, a transistor sitting on a layer of oxide, the way a lot of modern chips are built. It won’t solve yet. I narrowed it down to the oxide underneath the silicon, and I’m still wondering how breaks things. More on that next time.

random picture cause im too lazy to start the servers again