Method of manufacturing a semiconductor device

摘要

This invention provides a semiconductor device, which has a high impurity concentration diffusion region such as a drain diffusion region and a resistor comprising a polycrystalline silicon layer (which may be a load of a driver MOS transistor), and in which part of the resistor is in direct contact with the high impurity concentration diffusion region. This invention also provides a method of manufacturing a semiconductor device, which comprises the steps of forming a gate electrode and drain and source diffusion regions along the principal surface of a semiconductor substrate, then forming a polycrystalline silicon resistor layer of a comparatively low impurity concentration such that it is in direct contact with a diffusion region, and subsequently causing impurity diffusion from the diffusion region through thermal treatment to obtain ohmic contact between the diffusion region and resistor layer.