Semiconductor device

Abstract

This application discloses a semiconductor device comprising: an epitaxial substrate, a gate structure, a source electrode, and a drain electrode. The epitaxial substrate includes a semiconductor substrate, a buffer layer formed on the semiconductor substrate, a gallium nitride channel layer formed on the buffer layer, and a barrier layer formed on the gallium nitride channel layer. A two-dimensional electron gas is generated in the gallium nitride channel layer near the barrier layer. The gate structure, source electrode, and drain electrode are disposed on the epitaxial substrate, with the source electrode and drain electrode respectively disposed on opposite sides of the gate structure. One of the source electrode and drain electrode is connected to an antenna, and the other of the source electrode and drain electrode is connected to a tuning element. The gate structure is used to control the switching on and off of the tuning element and the antenna. Therefore, the breakdown capability of the semiconductor device can be increased, making it suitable for antenna tuning switches.

Claims

1. A semiconductor element used in an antenna tuner, the semiconductor element comprising: An epitaxial substrate includes a semiconductor substrate, a buffer layer formed on the semiconductor substrate, a gallium nitride channel layer formed on the buffer layer, and a barrier layer formed on the gallium nitride channel layer, wherein a two-dimensional electron gas (2DEG) is generated in the gallium nitride channel layer near the barrier layer; a gate structure is disposed on the epitaxial substrate; and a source electrode and a drain electrode are respectively disposed on opposite sides of the gate structure and respectively disposed on the epitaxial substrate, wherein one of the source electrode and the drain electrode is used to connect an antenna, and the other of the source electrode and the drain electrode is used to connect a tuning element, and the gate structure is used to control the on / off state of the tuning element and the antenna.

2. The semiconductor element as claimed in claim 1, wherein, The gate structure is a metal-insulator-semiconductor (MIS) structure, which includes a dielectric layer in contact with the epitaxial substrate and a gate electrode disposed on the dielectric layer.

3. The semiconductor element as claimed in claim 2, wherein, The gate electrode comprises titanium, aluminum, nickel, gold, platinum, chromium, copper, iridium, titanium nitride, its compounds, its composite layers or alloys thereof, and the dielectric layer is selected from the group consisting of silicon nitride (SiNx), silicon oxide (SiOx), hafnium oxide (HfOx) and aluminum oxide (AlOx) and combinations thereof.

4. The semiconductor element as claimed in claim 1, wherein, The gate structure includes a gallium nitride layer in contact with the epitaxial substrate and a gate electrode disposed on the gallium nitride layer, wherein a Schottky contact is formed between the gate electrode and the gallium nitride layer.

5. The semiconductor element as claimed in claim 4, wherein, The gate electrode includes titanium, aluminum, nickel, gold, platinum, chromium, copper, iridium, titanium nitride, or compounds thereof.

6. The semiconductor element as claimed in claim 1, wherein, The gate structure is a P-type gallium nitride gate.

7. The semiconductor element as claimed in claim 6, wherein, The P-type gallium nitride gate includes either carbon-doped gallium nitride or magnesium-doped gallium nitride.

8. The semiconductor element as claimed in claim 1, wherein, The gate structure is a fluorine-doped gallium nitride gate.

9. The semiconductor element as claimed in claim 1, wherein, The gate structure extends into the epitaxial substrate by a first distance, the first distance being less than or equal to 50 nanometers.

10. The semiconductor element as claimed in claim 1, wherein, The number of gate structures is N, where N is a positive integer less than or equal to 6, and the source electrode and the drain electrode are respectively disposed on opposite sides of the N gate structures.

11. The semiconductor element as claimed in claim 10, wherein, The distance between any two adjacent gate structures is greater than or equal to 0.5 micrometers and less than or equal to 4 micrometers.

12. The semiconductor element as claimed in claim 1, wherein, The source electrode and the drain electrode respectively form ohmic contacts with the epitaxial substrate.

13. The semiconductor element as claimed in claim 1, wherein, The source electrode and the drain electrode extend into the epitaxial substrate by a second distance, the second distance being less than or equal to 50 nanometers.

14. The semiconductor element as claimed in claim 1, wherein, The epitaxial substrate also includes a spacer layer disposed between the barrier layer and the gallium nitride channel layer.

15. The semiconductor element as claimed in claim 1, wherein, The epitaxial substrate also includes a capping layer disposed on the barrier layer.

16. The semiconductor element as claimed in claim 1, wherein, The semiconductor substrate has a resistivity greater than 500 ohm-cm.

17. The semiconductor element as claimed in claim 16, wherein, The semiconductor substrate is made of Si (111) or silicon carbide.

18. The semiconductor element as claimed in claim 1, wherein, The buffer layer includes carbon-doped gallium nitride (C-GaN), iron-doped gallium nitride (Fe-GaN), multiple stacked layers of carbon-doped gallium nitride and iron-doped gallium nitride, or aluminum gallium nitride back barrier layer.

19. The semiconductor element as claimed in claim 1, wherein, The distance between the gate structure and the source electrode, and the distance between the gate structure and the drain electrode, are greater than or equal to 0.5 micrometers and less than or equal to 4 micrometers.

20. The semiconductor element as claimed in claim 1, wherein, The barrier layer is made of aluminum gallium nitride (AlxGaN), with aluminum comprising 15% to 35% of the material.

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