Techniques are described to form a low-noise, high-gain semiconductor device. In one or more implementations, the device includes a substrate including a first dopant material having a concentration ranging from about 1×1010/cm3 to about 1×1019/cm3. The substrate also includes at least two active regions formed proximate to a surface of the substrate. The at least two active regions include a second dopant material, which is different than the first dopant material. The device further includes a gate structure formed over the surface of the substrate between the active regions. The gate structure includes a doped polycrystalline layer and an oxide layer formed over the surface between the surface and the doped polycrystalline layer. The doped polycrystalline layer includes the first dopant material having a concentration ranging from about 1×1019/cm3 to about 1×1021/cm3.