Don't press your finger down more than you need to. You just need enough energy to reach the bottom of the key.
Curve you finger
You've heard many times that you should curve your fingers. But why? All of our fingers have different lengths. We need to line up the fingers in a straight line so that we can control the fingers' movement easily and evenly. Grab a fat pen and place all of your fingers on the top. See? That is the perfect finger position. The most important thing to consider is to curve the first knuckle. If you do so, your finger tip will face the key at a 90 degree angle. The energy required to push the key is minimum. Remember, the smaller the area of a key you touch, the clearer your sound will be.
Drop and Roll
Try this "drop and roll" technique and you will learn how to relax and play lightly and clearly. The dropping energy at the beginning allows a relaxed finger motion to follow. Playing from little finger to thumb is easier first. Try 5 fingers, then one octave. When you can do this exercise with ease, I recommend you use Hanon No.38 for your routine finger exercise.