Robben found the net on a memorable night for the German champions with Thomas Muller's brace and Mario Gomez's close-range effort completing a staggering scoreline.
Bayern are now red-hot favourites to progress to the May showpiece at Wembley, with a below-par Barca needing a miracle in the semi-final second leg at Camp Nou next week.
But Robben told Sky Sports: "That is the strength of this team, we will keep focusing, there is always the next game. Let's stay concentrated, not talk too much and just play our football.
"I think it is quite impressive, the way we played. We can be very proud of tonight's game, we deserved the win.
"We didn't give them any opportunity to play their football. We have a lot of quality in the team and we can also score goals.
"The key to our performance tonight was that we played as a team, we fought for every metre and it was a great game.
"In these games you have to stand up as a player and as a team and I was happy about tonight.
"The most important thing was that we kept the field very compact and that's why we didn't give them any space to play. We made it very difficult."