Thin crust square-cut pizza isn't just Chicago thin, it's Midwest-style pizza. As noted, it's damn hard to get the crust right under the toppings. Inevitably, it either burns or grossly undercooked. I also like the pizza cooked longer so the cheese starts to brown over, but there are also some who like their pizza barely warm enough to melt the cheese. Gross.
There's a local frozen pizza out of Brainerd that has figured the crust out. I think it's called Giovanni's or somesuch.