Semiconductor device and method of manufacturing semiconductor device

A method of manufacturing a semiconductor device, comprising:

• preparing a semiconductor substrate;
• forming a first insulating film over the semiconductor substrate;
• after forming the first insulating film, forming first grooves in the first insulating film;
• forming a gate electrode and a first interconnect in the first grooves, respectively;
• forming a gate insulating film over the gate electrode;
• forming a semiconductor layer over the gate insulating film;
• forming a second insulating layer over the semiconductor layer and the first insulating film;
• forming a via in the second insulating layer;
• and
• forming a second interconnect over the second insulating film such that the second interconnect is connected to the semiconductor layer through the via,
• wherein the gate electrode and the first interconnect are formed by Cu or Cu alloy, respectively, and
• wherein the second interconnect is formed by Al or Al alloy.

A method of manufacturing a semiconductor device, comprising:

• forming a first insulating film over a semiconductor substrate;
• after forming the first insulating film, forming first grooves in the first insulating film;
• forming a gate electrode and a first interconnect in the first grooves, respectively;
• forming a gate insulating film over the gate electrode;
• forming a semiconductor layer over the gate insulating film;
• forming a second insulating layer over the semiconductor layer and the first insulating film;
• forming a via in the second insulating layer;
• and
• forming a second interconnect such that the second interconnect is connected to the semiconductor layer through the via,
• wherein the gate electrode and the first interconnect are formed by a first type alloy, respectively, and
• wherein the second interconnect is formed by a second type alloy different than the first type alloy.