Electronic device including a transistor and a field electrode
View Patent ↗In an aspect, a cascode circuit can include a high-side transistor and a low-side transistor. The source of the high-side transistor can be coupled to the drain of the low-side transistor; and the gate of the high-side transistor can be coupled to each of the source and the gate of the low-side transistor. In another aspect, an electronic device can include a high-side transistor, a low-side transistor, and a field electrode. The low-side transistor can include a drain region coupled to the source electrode of the high-side transistor. The field electrode can overlie and be capacitively coupled to a channel layer of the high-side transistor, wherein the field electrode is configured to be at a voltage between the voltages of the high-side and low-side power supply terminals.
1. An electronic device comprising:
a high-side transistor including:
a channel layer;
a drain electrode overlying the channel layer and coupled to a high-side power terminal; and
a source electrode overlying the channel layer;
a low-side transistor including:
a drain region coupled to the source electrode of the high-side transistor; and
a source region coupled a low-side power supply terminal; and
a field electrode overlying and capacitively coupled to the channel layer of the high-side transistor, wherein the field electrode is configured to be at a voltage between the voltages of the high-side and low-side power supply terminals.
2. The electronic device of claim 1 , wherein the low-side transistor further comprises a gate electrode that is coupled to the field electrode.
3. The electronic device of claim 2 , wherein the high-side transistor is a depletion-mode transistor, and the low-side transistor is an enhancement-mode transistor.
4. The electronic device of claim 1 , wherein the high-side transistor further comprises a gate electrode, wherein the field electrode overlies and is not electrically connected to the gate electrode of the high-side transistor.
5. The electronic device of claim 4 , wherein:
the gate electrode of the high-side transistor has an uppermost elevation at a location overlying the channel layer and between the source and drain electrodes of the high-side transistor; and
the field electrode includes a portion that lies at an elevation lower than the uppermost elevation at the location.
6. The electronic device of claim 5 , wherein the portion is laterally disposed between the gate electrode of the high-side transistor and the drain electrode of the high-side transistor.
7. The electronic device of claim 5 , wherein the portion is laterally disposed between the gate electrode of the high-side transistor and the source electrode of the high-side transistor.
8. The electronic device of claim 4 , wherein between the source and drain electrodes of the high-side transistor, a lowermost elevation of the field electrode is higher than an uppermost elevation of the gate electrode, and the lowermost elevation is less than 0.9 micron from the channel layer.
9. The electronic device of claim 4 , wherein the field electrode is capacitively coupled to the gate of the high-side transistor.
10. The electronic device of claim 9 , wherein:
the high-side transistor is a depletion-mode transistor;
the low-side transistor is an enhancement-mode transistor;
the drain electrode of the high-side transistor is electrically connected to the high-side power supply terminal;
the gate electrode of the high-side transistor is coupled to the source region of the low-side transistor;
the source electrode of the high-side transistor is electrically connected to the drain region of the low-side transistor;
the gate electrode of the low-side transistor is electrically connected to the field electrode; and
the source region of the low-side transistor is electrically connected to the low-side power supply terminal.