Creating Half Circle for Logo without Diameter Stroke

I am trying to create a logo in Illustrator and am getting slightly frustrated... Below is a screenshot of what I would like it to look like:

In this screenshot, the problem is in order to make the 1/2 circle, I had to draw a weird shape and fill it with white and place it under the text to hide the rest of the circle. However, when I export it and put the logo on a different background, the big white blob is visible because it's not transparent. I can't figure out how to make a half-circle without the diameter also being colored because of the stroke. Any help would be appreciated, thank you.