BBC provides a nice summary of Fed’s unconventional policy options
A brief note on interest rates paid on reserves:
The Federal Reserve began paying interest rates on reserves in late 2008. Originally authorized by the Financial Services Regulatory Relief Act of 2006, interest payments on reserve balances held (by depository institutions) at Reserve Banks was to begin in 2011. But, the effective date was advanced to October 2008 in response to the financial crisis by the Emergency Economic Stabilization Act of 2008.
Interest rate paid on required reserves is aimed at eliminating the implicit tax that reserve requirements imposed on depository institutions. Interest rate paid on excess reserves is actually a new policy tool available to the Federal Reserve. By varying interest rate on excess reserves, the Fed can potentially influence the quantity of excess reserves banks choose to hold (as opposed to lending it out).
Currently, interest rates on required reserve balances and on excess reserve balances have been set by the Federal Reserve Board at 25 basis points.