The Cumbrians fell to a 3-0 defeat in their northern area final second leg at Huddersfield on Tuesday night, but, after winning the opening encounter 4-0, have progressed to the final.
Clearly searching for an early goal, the Terriers dominated the opening exchanges and went ahead in the 30th minute when Anthony Pilkington fired home from 18 yards.
If the Cumbrians thought the first period was bad, they came under even more pressure in the second as Huddersfield sniffed a dramatic turnaround.
But, despite Alan Lee's two bullet headers on 70 and 81 minutes, Carlisle hung on to book a clash with Brentford on April 3.
Greg Abbott's men will be hoping to do better than last year when they fell to a 4-1 defeat against Southampton in the showpiece.