Harry Kane's goal lifted Spurs to a 1-0 win in the second leg at Signal Iduna Park on Tuesday, the Premier League side winning the last-16 tie 4-0 on aggregate.
Despite the result, Favre said there was plenty to like from Dortmund, who have won just one of their past eight matches in all competitions.
"All in all, it was a very good match. There were a lot of positives in the first half," he said.
"We might've lost 1-0 but the chance to qualify for the next round was lost in the first leg rather than the home fixture. I'll take a lot of positives.
"For me, there was only one team out there in the first half. We need to continue playing like that."
Dortmund had 19 shots against Tottenham, including seven on target, but were unable to find the breakthrough they needed.
Favre rued their failure to make the most of their opportunities, particularly in the first half.
"We showed a very good first-half performance with six goalscoring chances. Unfortunately, we couldn't get a goal," he said.
"We wanted to continue in that vein but then conceded a goal after three or four minutes in the second half and knew that it would then be very difficult as we needed five goals."
Forward Marco Reus was also dissapointed his side couldn't find a way through in the first half, but hopes they can build on the strong showing against Spurs in the opening 45.
"We needed a goal before half-time, we did not make it," he said.
"We had an incredible number of chances to score, but [Hugo Lloris] also did very well.
"We can build on the performance of the first half, which was strong after the setback to Augsburg.
"After the goal the game was decided.
"I think we do not currently have the momentum on our side. We have to work to shoot and finish even more often. Now we have to deliver in the next few weeks. It starts on Saturday. "