Great ideas above
I also want to add there's usually a reason they are trying to escape, so I would try to get the bottom of it first. For example, how many walks a day does he go on? A backyard is GREAT but it's kind of like children going to Chuck E Cheese. It's all fun and games with no rules and no boundaries and it's the same thing over and over again. He sounds like an explorer (believe me. Jackson is too!) so maybe take him for leashed walks around the neighborhood first and get his energy out so he doesn't want to escape the yard so much, ya know what I mean?