National Funding and Student Loans
Among scholarships designed specifically for studies abroad, you might also be able receive funding if you already have a scholarship for your studies in Germany. Many of the big foundations offer additional grants for a stay abroad. We recommend you to contact the foundation, from which you are currently receiving your scholarship, directly.
Finally, you can also to consider a student loan. If you are already advanced with your studies, you might be able to apply for the federal student loan (Bildungskredit), which has a very low interest rate.
Apart from that, many private banks offer student loans with (slightly) higher interest rates. You can find a recent comparison (in German language) here.