I don't know of any ornamental grasses, hardy to your zone, which will hit 5' in semi-shade. Tall grasses won't give you a year-round screen. They need to be cut to the ground in early spring, and take several months to regain their height.

Maybe there are some fast-growing conifers which will fill the bill.

There's a number of bamboos hardy to -15F if that fits your zone and most will tolerate part shade well. A good number of these will withstand even colder temperatures but may lose some foliage in very cold weather. Bamboo is an ideal screening plant if care is given to selection and proper planting.

And it's just another type of ornamental grass :-)

Most bamboo have VERY aggressive root systems. Do your research first.

As do a good many smaller scaled ornamental grasses. And as with the smaller OG's, bamboos come in both clumping and running forms. The runners do need containment, but that is quite easily accomplished with bamboo barrier sold for that purpose. Fortunately, some of the cold hardiest of the bamboos are clumpers and will behave just as politely as any clumping OG - no containment necessary.

Bamboo might be the answer .... The only problem with it in my zone 5 garden is that the leaves turn yellow and stay on the plant until very late in the spring. When other things are looking fresh and nice the bamboo is just starting to drop all its leaves in preparation for the new flush. I still like mine (the invasive type) but, I had to move them to a less viewed spot.

This year I bought two new clumping types and I hope that they will survive our winters ~ what am I saying?? We haven't actually had winter yet this year.

I'm guessing that if Ivan has shade he may also have other problems like roots and dry soil ..... Ivan, is the shade from large trees or from nearby buildings?

Donn suggested conifers, Garden Gal suggested bamboo and another possibility might be a combination climbing vines and a stucture for them to climb on. It doens't have to be a full out fence ~ a couple of staggered free standing trellis' would do the trick. There is a selection of climbing vines that would thrive in part shade. If you have problems with tree roots, the vines have the benefit of covering a large horizontal area with only a few small planting holes.
Just a thought......
Oh yes, If you choose a vine that has a woody stem it will give you some blockage from your neighbour all year round.