An order of removal made by the immigration judge at the conclusion of proceedings under section 240 of the Act shall become final:
(a) Upon dismissal of an appeal by the Board of Immigration Appeals;
(b) Upon waiver of appeal by the respondent;
(c) Upon expiration of the time allotted for an appeal if the respondent does not file an appeal within that time;
(d) If certified to the Board or Attorney General, upon the date of the subsequent decision ordering removal;
(e) If an immigration judge orders an alien removed in the alien's absence, immediately upon entry of such order; or
(f) If an immigration judge issues an alternate order of removal in connection with a grant of voluntary departure, upon overstay of the voluntary departure period, or upon the failure to post a required voluntary departure bond within 5 business days. If the respondent has filed a timely appeal with the Board, the order shall become final upon an order of removal by the Board or the Attorney General, or upon overstay of the voluntary departure period granted or reinstated by the Board or the Attorney General.