What Are Harvard Requirements For Granting Scholarships To Nigerian Students

My son would be writing waec next year and he is nursing the ambition of equally enrolling and sitting for the SAT exams in order to qualify for international scholarships.What requirements do Harvard university consider when considering students from west Africa especially Nigeria for scholarships,do they consider waec exam results as a proof of high school completion alongside with SAT results?Please anyone with useful information about this issue can share his views or his experience as it would be high welcomed.