The defender is already fantasising about reaching the final at Wembley and says BVB will do everything in their power to make their dream a reality
BVB saw off Malaga in their quarter-final with a stunning late show in the second leg, while los Blancos comfortably beat Galatasaray - leaving both clubs just two games from the final at Wembley.
And the Brazilian admits reaching the showpiece would be the realisation of a childhood dream, while speaking of the mutual respect between the two sides.
"If you're talking about the Champions League, of course it's our dream," the 27-year-old told Uefa.com.
"To play in the Champions League and to reach the final is the dream of not just me but that of all children born with the desire to play football.
"We are facing Real Madrid and we already know each other. There is mutual respect and we know about the difficulties. So we will put into practice everything we have shown so far in the Champions League, so we can leave [the second leg] with a victory and continue our dream."
Santana has done battle with both Mats Hummels and Neven Subotic for a centre-back slot this season and he believes the competition for places will prove to be a good thing in their quest for European success.
"Personally speaking, I think that in terms of how I feel as a player, I'm at 100% which is good for Borussia Dortmund," he added.
"Borussia Dortmund benefit because they have three [centre-halves] at the same level. And at any moment any of us can play and play well."