Blue screen iPhone 5S

I am worried because I have an iPhone 5S with iOS 7.1.2 and today after 8 months of use. Suddenly there was a blue screen and my iPhone will reboot. This occurred at the time you press the home button to turn off the iPhone 5s.

I worry that my device is broken ... I wonder if anyone has information about the origin and cause of this problem. My iPhone is a very careful and protected device has never dropped me, never hit, never have wet.

Best Regards

Nestor