Methods of adjusting a resistance of a buried resistor in a semiconductor are disclosed. In one aspect, the method includes using a silicidation blocking mask to define the buried resistor in the semiconductor; adjusting a size of the silicidation blocking mask to adjust a resistance of the buried resistor based on test data from a previous processing lot including a substantially similar buried resistor; and forming silicide on an area not covered by the silicidation blocking mask. The adjustment may be made by balancing the amount of the resistor that is covered with silicide versus un-silicided semiconductor to achieve the desired total resistance. The adjustment may be made according to an algorithm.