Semiconductor equipment

Abstract

To provide a semiconductor device with improved performance. [Solution] The semiconductor device includes a channel layer, a barrier layer located on the channel layer and containing a material having a different energy band gap from the channel layer, a gate electrode layer located on the barrier layer and extending in a first direction, a gate semiconductor layer located between the barrier layer and the gate electrode layer, and source electrodes and drain electrodes connected to the channel layer and located away from the gate electrode layer in a second direction different from the first direction. The gate electrode layer contains a metal nitride, and the gate electrode layer has a lower layer located on the gate semiconductor layer, an intermediate layer located on the lower layer, and an upper layer located on the intermediate layer in a third direction different from the first and second directions. In the gate electrode layer, the atomic ratio of nitrogen (N) to metal (M) of the metal nitride (N / M) is greater in the intermediate layer than in the lower layer, and even greater in the upper layer than in the intermediate layer.

Claims

1. Channel layer and A barrier layer located on the channel layer and comprising a material having a different energy band gap from the channel layer, A gate electrode layer located on the barrier layer and extending in a first direction, A gate semiconductor layer located between the barrier layer and the gate electrode layer, It includes a source electrode and a drain electrode connected to the channel layer and positioned apart from the gate electrode layer in a second direction different from the first direction, The gate electrode layer comprises a metal nitride, The gate electrode layer has a lower layer located on the gate semiconductor layer, an intermediate layer located on the lower layer, and an upper layer located on the intermediate layer, in a third direction different from the first and second directions. In the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to metal (M) in the metal nitride is greater in the intermediate layer than in the lower layer, and even greater in the upper layer than in the intermediate layer. Semiconductor equipment.

2. The metal nitrides include titanium nitride (TiN), titanium silicon nitride (TiSiN), tantalum nitride (TaN), tantalum silicon nitride (TaSiN), tantalum titanium nitride (TaTiN), titanium aluminum nitride (TiAlN), tantalum aluminum nitride (TaAlN), tungsten nitride (WN), titanium aluminum carbide nitride (TiAlC-N), or combinations thereof. The semiconductor device according to claim 1.

3. The aforementioned metal nitride includes titanium nitride (TiN), In the gate electrode layer, the atomic ratio of nitrogen (N) to titanium (Ti) in the titanium nitride (N / Ti) is greater in the intermediate layer than in the lower layer, and even greater in the upper layer than in the intermediate layer. The semiconductor device according to claim 2.

4. In the lower layer of the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to the metal (M) is 0.6 to less than 1.

0. In the upper layer of the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to the metal (M) is 1.0 to 1.

5. The semiconductor device according to claim 1.

5. In the intermediate layer of the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to the metal (M) is greater than 0.9 and less than 1.

2. The semiconductor device according to claim 1.

6. The thickness of the gate electrode layer is 500 Å to 2000 Å. The thicknesses of the lower layer, the intermediate layer, and the upper layer of the gate electrode layer are, each, 10 Å to 700 Å. The semiconductor device according to claim 1.

7. In the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to metal (M) in the metal nitride increases as it moves away from the gate semiconductor layer in the third direction. The semiconductor device according to claim 1.

8. In the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to metal (M) in the metal nitride increases stepwise or continuously as it moves away from the gate semiconductor layer in the third direction. The semiconductor device according to claim 7.

9. At the interface between the lower layer and the intermediate layer of the gate electrode layer, the atomic ratio (N / M) in the lower layer is the same as the atomic ratio (N / M) in the intermediate layer. At the interface between the intermediate layer and the upper layer, the atomic ratio (N / M) in the intermediate layer is the same as the atomic ratio (N / M) in the upper layer. The semiconductor device according to claim 8.

10. At the interface between the lower layer and the intermediate layer of the gate electrode layer, the atomic ratio (N / M) in the lower layer is smaller than the atomic ratio (N / M) in the intermediate layer. At the interface between the intermediate layer and the upper layer, the atomic ratio (N / M) in the intermediate layer is smaller than the atomic ratio (N / M) in the upper layer. The semiconductor device according to claim 8.

11. In the lower layer of the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to metal (M) in the metal nitride is constant, increases stepwise, or increases continuously as it moves away from the gate semiconductor layer in the third direction. In the intermediate layer of the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to metal (M) in the metal nitride is constant, increases stepwise, or increases continuously as it moves away from the gate semiconductor layer in the third direction. In the upper layer of the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to metal (M) in the metal nitride is constant, increases gradually, or increases continuously as it moves away from the gate semiconductor layer in the third direction. In any one layer selected from the group consisting of the lower layer, the intermediate layer, the upper layer, and combinations thereof, the atomic ratio (N / M) of nitrogen (N) to the metal (M) of the metal nitride increases as it moves away from the gate semiconductor layer in the third direction. The semiconductor device according to claim 8.

12. In the gate electrode layer, the rate at which the atomic ratio (N / M) of nitrogen (N) to metal (M) in the metal nitride increases as it moves away from the gate semiconductor layer in the third direction is constant, decreases, or increases. The semiconductor device according to claim 11.

13. In the lower layer of the gate electrode layer, the rate at which the atomic ratio (N / M) of nitrogen (N) to metal (M) of the metal nitride increases as it moves away from the gate semiconductor layer in the third direction is constant, decreases, or increases. In the intermediate layer of the gate electrode layer, the rate at which the atomic ratio (N / M) of nitrogen (N) to metal (M) of the metal nitride increases as it moves away from the gate semiconductor layer in the third direction is constant, decreases, or increases. In the upper layer of the gate electrode layer, the rate at which the atomic ratio (N / M) of nitrogen (N) to metal (M) of the metal nitride increases as it moves away from the gate semiconductor layer in the third direction is constant, decreases, or increases. The semiconductor device according to claim 12.

14. The atomic ratio (N / M) in the lower layer of the gate electrode layer is constant, or increases while the rate of increase is kept constant. The atomic ratio (N / M) in the intermediate layer increases while the rate of increase remains constant. The atomic ratio (N / M) in the upper layer is either constant or increases while the rate of increase remains constant. The rate of increase of the atomic ratio (N / M) in the intermediate layer is greater than the rate of increase of the atomic ratio (N / M) in the lower layer and the rate of increase of the atomic ratio (N / M) in the upper layer. At the interface between the lower layer and the intermediate layer of the gate electrode layer, the atomic ratio (N / M) in the lower layer is the same as the atomic ratio (N / M) in the intermediate layer, and at the interface between the intermediate layer and the upper layer, the atomic ratio (N / M) in the intermediate layer is the same as the atomic ratio (N / M) in the upper layer. The semiconductor device according to claim 13.

15. The atomic ratio (N / M) in the lower layer of the gate electrode layer increases while the rate of increase decreases. The atomic ratio (N / M) in the intermediate layer is either constant or increases while the rate of increase remains constant. The atomic ratio (N / M) in the upper layer is either constant or increases while the rate of increase remains constant. The rate of increase of the atomic ratio (N / M) in the lower layer is greater than the rate of increase of the atomic ratio (N / M) in the intermediate layer and the rate of increase of the atomic ratio (N / M) in the upper layer. At the interface between the lower layer and the intermediate layer of the gate electrode layer, the atomic ratio (N / M) in the lower layer is the same as the atomic ratio (N / M) in the intermediate layer, and at the interface between the intermediate layer and the upper layer, the atomic ratio (N / M) in the intermediate layer is the same as the atomic ratio (N / M) in the upper layer. The semiconductor device according to claim 13.

16. The atomic ratio (N / M) in the lower layer of the gate electrode layer increases while the rate of increase remains constant. The atomic ratio (N / M) in the intermediate layer increases while the rate of increase remains constant. The atomic ratio (N / M) in the upper layer increases while the rate of increase remains constant. The rate of increase of the atomic ratio (N / M) in the lower layer is greater than the rate of increase of the atomic ratio (N / M) in the intermediate layer and the rate of increase of the atomic ratio (N / M) in the upper layer. At the interface between the lower layer and the intermediate layer of the gate electrode layer, the atomic ratio (N / M) in the lower layer is smaller than the atomic ratio (N / M) in the intermediate layer, and at the interface between the intermediate layer and the upper layer, the atomic ratio (N / M) in the intermediate layer is the same as the atomic ratio (N / M) in the upper layer. The semiconductor device according to claim 13.

17. The atomic ratio (N / M) in the lower layer of the gate electrode layer increases as the rate of increase increases, The atomic ratio (N / M) in the intermediate layer is either constant or increases while the rate of increase remains constant. The atomic ratio (N / M) in the upper layer is either constant or increases while the rate of increase remains constant. The rate of increase of the atomic ratio (N / M) in the lower layer is greater than the rate of increase of the atomic ratio (N / M) in the intermediate layer and the rate of increase of the atomic ratio (N / M) in the upper layer. At the interface between the lower layer and the intermediate layer of the gate electrode layer, the atomic ratio (N / M) in the lower layer is the same as the atomic ratio (N / M) in the intermediate layer, and at the interface between the intermediate layer and the upper layer, the atomic ratio (N / M) in the intermediate layer is the same as the atomic ratio (N / M) in the upper layer. The semiconductor device according to claim 13.

18. Channel layer and A barrier layer located on the channel layer and comprising a material having a different energy band gap from the channel layer, A gate electrode layer located on the barrier layer and extending in a first direction, A gate semiconductor layer located between the barrier layer and the gate electrode layer, It includes a source electrode and a drain electrode connected to the channel layer and positioned apart from the gate electrode layer in a second direction different from the first direction, The gate electrode layer has a lower layer located on the gate semiconductor layer, an intermediate layer located on the lower layer, and an upper layer located on the intermediate layer, in a third direction different from the first and second directions. The work function of the gate electrode layer is smaller in the intermediate layer than in the lower layer, and even smaller in the upper layer than in the intermediate layer. Semiconductor equipment.

19. Channel layer and A barrier layer located on the channel layer and comprising a material having a different energy band gap from the channel layer, A gate electrode layer located on the barrier layer and extending in a first direction, A gate semiconductor layer located between the barrier layer and the gate electrode layer, It includes a source electrode and a drain electrode connected to the channel layer and positioned apart from the gate electrode layer in a second direction different from the first direction, The gate electrode layer comprises a metal nitride, The gate electrode layer has a lower layer located on the gate semiconductor layer, an intermediate layer located on the lower layer, and an upper layer located on the intermediate layer, in a third direction different from the first and second directions. In the gate electrode layer, the atomic ratio (N / M) of nitrogen (N) to metal (M) in the metal nitride is greater in the upper layer than in the lower layer. The length of the upper surface of the gate electrode layer in the second direction is smaller than the length of the lower surface of the gate electrode layer in the second direction. Semiconductor equipment.

20. The semiconductor device further includes a hard mask layer located on the gate electrode layer. The semiconductor device according to claim 19.

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