It will be the German's second final of the season after winning in Munich in May. Taking the title would move him into the top 20 for the first time.
Kohlschreiber, looking for his fifth career title, has never played Haase before. The Dutchman won his lone title here last year.
Kohlschreiber was broken while serving for the first set at 5-3, the only time he dropped serve in the match. He recovered to break Volandri twice in both the following sets. The Italian has now failed to win a match against a top-30 player in 26 straight attempts.
Haase won 26 of his 27 first-serve points to control his semifinal against Klizan, who had not been in the quarterfinals of an ATP event before.