Method of forming electronic components with increased reliability
An electronic component includes a depletion-mode transistor, an enhancement-mode transistor, and a resistor. The depletion-mode transistor has a higher breakdown voltage than the enhancement-mode transistor. A first terminal of the resistor is electrically connected to a source of the enhancement-mode transistor, and a second terminal of the resistor and a source of the depletion-mode transistor are each electrically connected to a drain of the enhancement-mode transistor. A gate of the depletion-mode transistor can be electrically connected to a source of the enhancement-mode transistor.
1. A method of producing an electronic component, the method comprising:
providing an enhancement-mode transistor having a first threshold voltage and a first breakdown voltage, the enhancement-mode transistor comprising a first source, a first gate, and a first drain;
providing a depletion-mode transistor having a second breakdown voltage which is larger than the first breakdown voltage, the depletion-mode transistor having a second threshold voltage, the depletion-mode transistor comprising a second source, a second gate, and a second drain; and
connecting the second source to the first drain; wherein
at a first temperature, an off-state drain current of the enhancement-mode transistor under a first bias condition is greater than an off-state source current of the depletion-mode transistor under a second bias condition;
under the first bias condition, a first voltage of the first gate relative to the first source is less than the first threshold voltage, and a second voltage of the second drain relative to the first source is greater than the first breakdown voltage and less than the second breakdown voltage; and
under the second bias condition, a third voltage of the second gate relative to the second source is less than the second threshold voltage, and a fourth voltage of the second drain relative to the second gate is equal to the second voltage.
2. The method of claim 1 , wherein under the first bias condition, the first voltage is less than or equal to 0V.
3. The method of claim 2 , wherein under the second bias condition, an absolute value of the third voltage is less than the first breakdown voltage.
4. The method of claim 1 , wherein the first temperature is 25° C.
5. The method of claim 1 , the electronic component being rated to operate at a temperature range between and including a second temperature and a third temperature, wherein the second temperature is less than the first temperature and the third temperature is greater than the second temperature, and the off-state drain current of the enhancement-mode transistor under the first bias condition is greater than the off-state source current of the depletion-mode transistor under the second bias condition at all temperatures within the temperature range.
6. The method of claim 5 , wherein the second temperature is −55° C. and the third temperature is 200° C.
7. The method of claim 1 , wherein the off-state source current of the depletion-mode transistor under the second bias condition is less than 0.75 times the off-state drain current of the enhancement-mode transistor under the first bias condition.
8. The method of claim 1 , wherein at a second temperature, the off-state drain current of the enhancement-mode transistor under a third bias condition is less than the off-state source current of the depletion-mode transistor under the second bias condition, wherein under the third bias condition, the first voltage is less than the first threshold voltage, and a fifth voltage of the first drain relative to the first source is less than the first breakdown voltage.
9. The method of claim 8 , wherein under the third bias condition, the first voltage is less than or equal to 0V.
10. The method of claim 8 , wherein the second temperature is less than the first temperature.
11. The method of claim 8 , further comprising connecting a first terminal of a current-carrying component to the first source or to the second gate, and connecting a second terminal of the current-carrying component to the first drain or to the second source.
12. The method of claim 11 , wherein the current-carrying component comprises a resistor.
13. The method of claim 11 , wherein the current-carrying component comprises a diode.
14. The method of claim 1 , further comprising connecting the second gate to the first source.
15. The method of claim 1 , wherein the second breakdown voltage is at least three times the first breakdown voltage.
16. The method of claim 1 , wherein the enhancement-mode transistor or the depletion-mode transistor is a III-N device.
17. The method of claim 1 , wherein the enhancement-mode transistor is a silicon-based transistor, and the depletion-mode transistor is a III-N transistor.
18. The method of claim 1 , wherein the depletion-mode transistor is a III-N transistor comprising a III-N buffer structure, a III-N channel layer, and a III-N barrier layer, and the buffer structure is doped with iron, magnesium, or carbon.
19. The method of claim 18 , wherein a first layer of the III-N buffer structure is at least 0.8 microns thick and is doped with Fe and C, the concentration of Fe being at least 8×10 17 cm −3 .