The German champions won 3-0 at the Camp Nou on Wednesday night as they hammered their Spanish opponents in the last four of the competition.
Bayern will now face domestic rivals Borussia Dortmund in the final at Wembley Stadium later this month.
"To perform like this, playing against a team that has dominated Europe over the last five years with so much quality in their squad, if we win 4-0 and 3-0 away, especially the 3-0 here, it is amazing," Robben told Sky Sports News.
"Now we are in the final - for the third time in the last four years and it is time to win it now.
"It is going to be a big one. Dortmund has proved over the last two or three years they are a very good team and it will be decided on small details."
Bayern and Dortmund will meet before the final on May 25 when they play each other in the Bundesliga on Saturday.