Micro Stakes Online NL : 25NL AKs FD vs short stack

vilain is unknown...6 hands played vs him.

Full Tilt Poker $0.10/$0.25 No Limit Hold'em - 6 players - View hand 829544
The Official DeucesCracked.com Hand History Converter

Hero (MP): $25.00
CO: $35.14
BTN: $26.50
SB: $76.36
BB: $8.85
UTG: $25.00

Pre Flop: ($0.35) Hero is MP with K A
1 fold, Hero raises to $0.85, 3 folds, BB calls $0.60

Flop: ($1.80) 8 9 6 (2 players)
BB bets $0.75, Hero raises to $3, BB calls $2.25

Turn: ($7.80) 2 (2 players)
BB checks, Hero bets $21.15 all in

Final Pot: $7.80

is it better to just call on the flop or to raise? And what about the turn play?