Scorpions like cool, wet places... especially wood. You need to take a multi-pronged approach if you want to get rid of them.
Create a vegetative-free zone around your house using rock... a foot and a half or so should do. This also helps drainage around your foundation, so it's a good idea anyway. Seal areas where they could be getting in like holes around faucets, doors, windows, and chimneys. Move anything like piles of firewood away from the house.
They prey on other insects, so remove any of their food sources that you can find. Treat the yard every few months. (Despite my otherwise hippie nature, my favorite DIY treatment is triazicide.) Inside the house, you can use traps with water and boron (the scorpions are attracted to the water and the boron kills them), and treat areas like your attic and around baseboards with dessicating powders ... even food-safe powders work, like talcum powder and medicated body powder.