Dear Pixwah,
No you are not legally required to be listed as the child's father on the birth certificate or to sign it, even if you are the biological father. The birth certificate will then be submitted with only the mother's details.
However, if you are simply trying to avoid any financial obligations, remember that a life is at stake, that is half you. It is important for a child to know the identity of their biological father for many reasons. Even if you do not intend to be involved in the child's life, they should be able to trace their ancestry.
Call the CSA (Child Support Agency) to get more information on your rights and responsibilities.