The real father of Ebrahim was a believer as we read in Quran that Ebrahim prayed for his parents ( O My Lord, Forgive me and my parents on the Day of Judgement) (Sura Ebrahim, Verse 41). It is not allowed to pray for forgiveness of polytheist. (Sura Al-Tawbah, verse 114) which is clear that Ebrahim did not pray for his disbeliever uncle but did pray for his believer real father.
Azar who was mentioned in Quran (Sura Al-An'am, Verse 74) was not the real father of Ebrahim, but was his uncle. His real father's name is Taarih تارح. Arabic language allows to call the uncle as father أبو but the real father is called والد parent.
'In Quran, Allah (SWT) mentioned Esmael as one of the fathers of Yaqoub Jacob though he was his uncle (Sura Al-Baqara, verse 133).