Fostering the ties of kinship is a most excellent deed in Islam. So, you should try to connect with your half-brother and help him as much as you can. However, you should never spoil him.  It is what we learn from the Prophet`s examples:  While helping people who came to him for help, he always taught them to be self-reliant. He once told a man to go and collect dry wood from the forest and sell them and earn a living by the sweat of his labor.

 

They say: it is better to teach a man how to fish rather than giving him a fish.

 

So, never allow your brother to be lazy solely depending on your handouts; rather he should learn to find an independent source of livelihood.

 

Almighty Allah knows best.