After taking three steps backwards, one must remain standing in that place. He may not immediately return to where he prayed the Amidah, for if he does, he resembles a dog that returns to its vomit (Yoma 53b). The reason for this condemnation is that after separating himself from the King, if he returns to stand before Him, only to wait there without reason, he illustrates that he did not comprehend that he was standing before the King and that he already separated from Him. Therefore, his action is considered disgraceful. There are those who continue to err, and upon returning to their places they lift their heels slightly as done in Kedushah. However, there is no reason for this.
L’chatchilah, one should stand in the place that his steps ended until the chazan arrives at Kedushah, or at least until the chazan starts the repetition of the Amidah (Shulchan Aruch 123:2). According to the majority of poskim, there is no need to remain standing with one’s feet together upon the conclusion of Oseh shalom (Mishnah Berurah 123:6; Bei’ur Halachah and Sha’ar HaTziyun there). However, there are those who say that it is good to remain with one’s legs together until he returns to his place. (Kitzur Shulchan Aruch 18:13; Kaf HaChaim 123:11 mentions both opinions.)
It is proper that even someone praying individually does not return immediately to his original place, but stops after taking three steps, and waits in his place for the amount of time it takes the chazan to arrive at Kedushah, which is approximately half a minute. In extenuating circumstances, if he must return to his place, he must wait the amount of time it takes to walk four amot and only then return (Mishnah Berurah 123:11; Kaf HaChaim 20). The chazan who must begin the Amidah repetition, can l’chatchilah wait in the place his steps ended, approximately the walking time of only four amot, and afterwards return to his place, because he is approaching the Amidah prayer again (Rama 123:2). Similarly, one who must make up a missed prayer, and pray a supplementary prayer (tashlumim), must wait approximately the amount of time it takes to walk four amot and then return to pray (Mishnah Berurah 123:11).
At the end of the Amidah repetition, it is unnecessary for the chazan to take three steps back again, since his prayer is not completely concluded until Kaddish-Titkabal, in which he requests that his prayers and requests be accepted. At the end of Kaddish-Titkabal, he takes three steps back and says Oseh shalom (Shulchan Aruch 123:5). Although in Shacharit we recite Tachanun, Ashrei, and U’va L’Tzion before the Kaddish, and on Mondays and Thursdays the Torah is read, nevertheless, the chazan’s separation from the Amidah repetition occurs in the Kaddish-Titkabal recited after U’va L’Tzion. Therefore, the chazan must be strict not to talk from the end of the Amidah repetition until the end of Kaddish-Titkabal (Mishnah Berurah 123:18).