unfortunately, petitioning for a brother to go to the US is close to impossible...if i am not mistaken, the US now denies sibling-to-sibling petitioning, at least in the Philippines. It will serve the half-brother better if the father petitions him. However, not meaning to dampen your spirit, but even with the dad submitting a petition for the brother, it will still take years. I have been told that petition papers processing for the Philippines are only in the 1996 petitions. So good luck.
By the way, forgive me for using third-person view on this reply. I am not sure if you were referring to yourself or your half-brother as the one who wants or is needing to be filed a petition for.