US Patent 10134859 Transistor with asymmetric spacers

A field-effect transistor device including an asymmetric spacer assembly allows lower parasitic capacitance on the drain side of the device and lower resistance on the source side. The asymmetric spacer assembly is formed by a self-aligned process, resulting in less gate/junction overlap on the drain side of the device and greater gate/junction overlap on the source side of the device. Asymmetric transistors having small gate lengths can be obtained without overlay/misalignment issues.