Do you think I should confront my father about him being so unkind to my younger brother?
How does your father treat your brother?
He screams and yells at him for no reason.
That is sad.  It is important to stand up for someone who isn't being treated fairly.
I love my dad but I think it's fair to stand up for my brother.
I agree, but you should probably give a lot of thought as to how to approach your dad. You don't want to be too aggressive and accusatory. Try to remember that the goal is to make things better for your brother, not just to confront your father.