Bidirectional switch
View Patent ↗A bidirectional switch includes a plurality of unit cells 11 including a first ohmic electrode 15 , a first gate electrode 17 , a second gate electrode 18 , and a second ohmic electrode 16 . The first gate electrodes 15 are electrically connected via a first interconnection 31 to a first gate electrode pad 43 . The second gate electrodes 18 are electrically connected via a second interconnection 32 to a second gate electrode pad 44 . A unit cell 11 including a first gate electrode 17 having the shortest interconnect distance from the first gate electrode pad 43 includes a second gate electrode 18 having the shortest interconnect distance from the second gate electrode pad 44.
1. A bidirectional switch comprising:
a plurality of unit cells including a semiconductor layer formed on a substrate, and a first ohmic electrode, a first gate electrode, a second gate electrode, and a second ohmic electrode successively formed on the semiconductor layer and spaced from each other;
a first interconnection formed on the semiconductor layer, electrically connecting the first gate electrodes, and extending in a direction intersecting the first gate electrodes;
a second interconnection formed on a side opposite to the first interconnection with the unit cells being interposed between the first and second interconnections, connecting the second gate electrodes, and extending in a direction intersecting the second gate electrodes;
a first gate electrode pad electrically connected to the first interconnection; and
a second gate electrode pad electrically connected to the second interconnection,
wherein
the entire first interconnection is overlapped by the first gate electrode pad in plan view, and
the entire second interconnection is overlapped by the second gate electrode pad in plan view.
2. The bidirectional switch of claim 1 , wherein in each of the plurality of unit cells, an interconnect distance between the first gate electrode and the first gate electrode pad is equal to an interconnect distance between the second gate electrode and the second gate electrode pad.
3. The bidirectional switch of claim 1 , wherein the first and second gate electrode pads are symmetrical about a center line of the semiconductor substrate extending in a direction in which the first and second interconnections extend.
4. The bidirectional switch of claim 2 , wherein the first and second gate electrode pads are symmetrical about a center point of the semiconductor substrate.
5. The bidirectional switch of claim 1 , wherein the first and second gate electrode pads are unitary with the first and second interconnections, respectively.
6. The bidirectional switch of claim 1 , further comprising:
a first ohmic electrode pad electrically connected to the first ohmic electrode; and
a second ohmic electrode pad electrically connected to the second ohmic electrode,
wherein
the semiconductor layer has an active region and a high-resistance region surrounding the active region, and
at least a portion of the first and second ohmic electrode pads is formed on the active region.
7. The bidirectional switch of claim 6 , wherein at least a portion of the first and second gate electrode pads is formed on the active region.
8. The bidirectional switch of claim 1 , further comprising:
a first ohmic electrode pad electrically connected to the first ohmic electrode; and
a second ohmic electrode pad electrically connected to the second ohmic electrode,
wherein
the second ohmic electrode pad is formed on the semiconductor layer, and
the first ohmic electrode pad is formed on a surface of the semiconductor substrate opposite to a surface of the semiconductor substrate on which the semiconductor layer is formed.
9. The bidirectional switch of claim 1 , wherein the semiconductor layer includes a first nitride semiconductor layer and a second nitride semiconductor layer having a larger band gap than that of the first nitride semiconductor layer, the first and second nitride semiconductor layers being successively formed, and the first nitride semiconductor layer being closer to the substrate than the second nitride semiconductor layer is.
10. The bidirectional switch of claim 1 , wherein a portion of the first ohmic electrode is overlapped by the first gate electrode pad in plan view.
11. The bidirectional switch of claim 10 , wherein a portion of the second ohmic electrode is overlapped by the first gate electrode pad in plan view.