A Hall-effect magnetic sensor comprises a p-type Hall element and an n-type epitaxial Hall element. The p-type element can be implanted directly on top of the n-type element. The merged Hall elements can be biased in parallel to provide a nearly zero-bias depletion layer throughout for isolation. Electrical contacts to the n-type element can be diffused down through the p-type element and positioned to partially obstruct current flow in the p-type element. Electrical contacts can be diffused into the p-type element. Each bias contact of the p-type element can be connected to respective bias contacts of the n-type element in a parallel fashion. Then, an output signal can be taken at the sense contacts of the n-type element in order to provide improved magnetic responsivity. Further provided is a method for manufacturing the Hall-effect magnetic sensor.