Semiconductor device and method for producing same
A semiconductor device 1 has an electrode structure that includes source electrodes 3 , a gate electrode 4 , and drain electrodes 5 disposed on a semiconductor laminated structure 2 and extending in parallel to each other and in a predetermined first direction and a wiring structure that includes source wirings 9 , drain wirings 10 , and gate wirings 11 disposed on the electrode structure and extending in parallel to each other and in a second direction orthogonal to the first direction. The source wirings 9 , the drain wirings 10 , and the gate wirings 11 are electrically connected to the source electrodes 3 , the drain electrodes 5 , and the gate electrode 4 , respectively. The semiconductor device 1 includes a conductive film 8 disposed between the gate electrode 4 and the drain wirings 10 and being electrically connected to the source electrodes 3.
1. A semiconductor device having a source electrode, a gate electrode, and a drain electrode disposed on a semiconductor laminated structure; a source wiring electrically connected to the source electrode; a drain wiring electrically connected to the drain electrode; a gate wiring connected to the gate electrode,
the semiconductor device comprising: a first conductive film, a second conductive film electrically connected to the source electrode, and a third conductive film electrically connected to the source electrode,
wherein in a certain cross section,
the first conductive film is disposed between the source electrode and the gate electrode, the second conductive film is disposed between the gate electrode and the drain electrode, and an upper surface thereof is disposed closer to the semiconductor laminated structure than an upper surface of the gate electrode, and
the third conductive film is disposed above the gate electrode and below the drain wiring.
2. The semiconductor device according to claim 1 , wherein the first conductive film has a portion extending in a direction parallel to a surface of the semiconductor laminated structure.
3. The semiconductor device according to claim 2 , wherein the second conductive film has a portion extending in a direction parallel to a surface of said semiconductor laminated structure.
4. The semiconductor device according to claim 3 , wherein the third conductive film has a portion extending in a direction parallel to a surface of said semiconductor laminated structure.
5. The semiconductor device according to claim 4 , wherein the first conductive film is formed in the same layer as the second conductive film.
6. The semiconductor device according to claim 5 , wherein the source wiring is connected to the source electrode via a source via metal whose material is different from that of the source electrode;
the drain wiring is connected to the drain electrode via a drain via metal whose material is different from that of the drain electrode,
the gate wiring is connected to the gate electrode via a gate via metal whose material is different from that of the gate electrode,
wherein the source electrode and the drain electrode are composed of a Ti/AlSiCu/Ti/TiN laminated film in which a Ti film, an AlSiCu film, a Ti film and a TiN film are laminated in this order from a lower layer.
7. The semiconductor device according to claim 6 , wherein the gate electrode is composed of a TiN/W/AlCu/TiN laminated film in which a TiN film, a W film, an AlCu film and a TiN film are laminated in that order from a lower layer.
8. The semiconductor according to claim 7 , wherein the source wiring, the drain wiring and the gate wiring are composed of a TiN/AlCu/TiN laminated film in which a TiN film, an AlCu film and a TiN film are laminated in that order from a lower layer.
9. The semiconductor device according to claim 8 , wherein the source electrode, the gate electrode and the drain electrode extend in a predetermined first direction, and
the third conductive film extends in the first direction along the upper surface of the gate electrode.
10. The semiconductor device according to claim 9 , wherein a width of the third conductive film is greater than a width of the upper surface of the gate electrode, and in plan view, each side edge of the third conductive film projects further outward from a corresponding side edge of the upper surface of the gate electrode.
11. The semiconductor device according to claim 10 , wherein an amount of projection of each side edge of the third conductive film from the corresponding side edge of the upper surface of the gate electrode is not less than 0.3 μm and not more than 0.9 μm.
12. The semiconductor device according to claim 11 , wherein a distance between the upper surface of the gate electrode and a lower surface of the third conductive film is not less than 0.15 μm and not more than 0.25 μm.
13. The semiconductor device according to claim 12 , wherein the source electrode and the drain electrode are disposed apart from the gate electrode such as to sandwich the gate electrode.
14. The semiconductor device according to claim 13 , wherein the semiconductor laminated structure includes an active area including an element structure arranged by sandwiching the gate electrode with the source electrode and the drain electrode and a nonactive area outside the active area and
in the nonactive area, the source wiring and the third conductive film are electrically connected.
15. The semiconductor device according to claim 14 , wherein the semiconductor laminated structure includes an electron transit layer and an electron supply layer formed on the electron transit layer and having formed therein a lower opening portion reaching the electron transit layer,
an insulating layer having an upper opening portion in communication with the lower opening portion is formed on the semiconductor laminated structure,
a gate insulating film is formed such as to cover a front surface of the insulating layer and a bottom portion and a side portion of a gate opening portion constituted of the lower opening portion and the upper opening portion, and
the gate electrode is formed on the gate insulating film inside the gate opening portion.
16. The semiconductor device according to claim 15 , wherein the second conductive film is embedded in the insulating layer between the gate electrode and the drain electrode, is insulated from the gate electrode, and is electrically connected to the source electrode, and
the second conductive film is exposed at an intermediate height position on one side of the gate opening.
17. The semiconductor device according to claim 16 , wherein the first conductive film is embedded in the insulating layer between the gate electrode and the source electrode and is insulated from the gate electrode and the source electrode.
18. The semiconductor device according to claim 17 , further comprising: a side wall of an insulating property disposed between the gate insulating film and the side portion of the gate opening portion.
19. The semiconductor device according to claim 18 , wherein the gate electrode includes an overlap portion formed on the gate insulating film at a peripheral edge of the gate opening portion.
20. The semiconductor device according to claim 19 , wherein the source via metal, the drain via metal and the gate via metal are embedded in a source via hole, a drain via hole and a gate via hole, respectively, and
the source via metal, the drain via metal and the gate via metal are composed of a TiN barrier film formed on sidewalls of the corresponding via holes and tungsten buried inside the TiN barrier film.
21. The semiconductor device according to claim 20 , wherein the first conductive film is electrically connected to none of the source electrode, the gate electrode and the drain electrode.