The 74AHCT14 IC contains six Inverting Schmitt Triggers. Schmitt triggers can be used for creating a sharp signal transition from a smooth curve. This is useful when feeding an RC-debounced signal into a hardware interrupt.
Download the 74AHCT14 Datasheet (PDF)
Buy a 74AHCT14 Hex Inverting Schmitt Trigger from Amazon, Adafruit, or Digi-Key.