Look for plastic deer netting. I use that around planters where I need to keep out my chickens. The netting can be bought in varying heights and cut to length. It's easily stapled to light wooded posts.
As long as a chicken can't see a sturdy landing on top of any fence, they will not try to get over it. They almost always fly up to the top of a barrier, land, then fly down on the other side, rarely taking flight and clearing the top of a fence. A three foot fence is usually enough to keep chickens on the side where you want them as long as there are no solid horizontal wood fencing.