Semiconductor device and manufacturing method of the same
A semiconductor device includes a buffer layer formed with a semiconductor adapted to produce piezoelectric polarization, and a channel layer stacked on the buffer layer, wherein a two-dimensional hole gas, generated in the channel layer by piezoelectric polarization of the buffer layer, is used as a carrier of the channel layer. On a complementary semiconductor device, the semiconductor device described above and an n-type field effect transistor are formed on the same compound semiconductor substrate. Also, a level shift circuit is manufactured by using the semiconductor device. Further, a semiconductor device manufacturing method includes forming a compound semiconductor base portion, forming a buffer layer on the base portion, forming a channel layer on the buffer layer, forming a gate on the channel layer, and forming a drain and source with the gate therebetween on the channel layer.
1. A semiconductor device comprising:
an undoped buffer layer formed with an indium gallium phosphide (InGaP) semiconductor adapted to produce piezoelectric polarization; and
a channel layer stacked on the undoped buffer layer,
wherein a two-dimensional hole gas, generated in the channel layer by the piezoelectric polarization of the undoped buffer layer, is used as a carrier of the channel layer.
2. The semiconductor device of claim 1 , wherein the channel layer is formed with a semiconductor having a higher energy level of the valence band than the undoped buffer layer.
3. The semiconductor device of claim 1 , wherein the two-dimensional hole gas is generated in the channel layer by the piezoelectric polarization in an amount proportional to a thickness of the undoped buffer layer.
4. The semiconductor device of claim 1 , wherein the undoped buffer layer is formed with a plurality of semiconductor layers, wherein each layer of the plurality of semiconductor layers lattice-matches an adjacent layer of the plurality of semiconductor layers, and
a layer of the plurality of semiconductor layers provided adjacent to the channel layer is formed with the InGaP semiconductor adapted to produce the piezoelectric polarization.
5. The semiconductor device of claim 1 , wherein the channel layer is formed by stacking a semiconductor that lattice-matches the InGaP semiconductor adapted to produce the piezoelectric polarization.
6. The semiconductor device of claim 1 , wherein a semiconductor of the channel layer is doped with C, Zn or Be as an impurity at a concentration of 1×10 17 atoms/cm 3 or less.
7. The semiconductor device of claim 1 , wherein the undoped buffer layer is stacked on a compound semiconductor substrate, and
at least one semiconductor layer is stacked between the undoped buffer layer and compound semiconductor substrate, and the at least one semiconductor layer lattice-matches semiconductors of both the undoped buffer layer and the compound semiconductor substrate and has a band gap different from those of the semiconductors of both the undoped buffer layer and the compound semiconductor substrate.
8. The semiconductor device of claim 1 comprising: a gate formed with an n-type semiconductor stacked on the channel layer.
9. The semiconductor device of claim 1 comprising: a gate formed by diffusing an n-type impurity into the channel layer.
10. The semiconductor device of claim 1 comprising: a gate formed with a schottky metal joined to the channel layer.
11. The semiconductor device of claim 1 comprising: a gate formed by joining a schottky metal to a gate oxide film stacked on the channel layer.
12. A circuit manufactured using a semiconductor device including:
an undoped buffer layer formed with an indium gallium phosphide (InGaP) semiconductor adapted to produce piezoelectric polarization; and
a channel layer stacked on the undoped buffer layer,
wherein a two-dimensional hole gas, generated in the channel layer by piezoelectric polarization of the undoped buffer layer, is used as a carrier of the channel layer.
13. A semiconductor device comprising:
an undoped buffer layer formed with a semiconductor adapted to produce piezoelectric polarization, wherein the semiconductor is In 0.51 Ga 0.49 P; and
a channel layer stacked on the undoped buffer layer,
wherein a two-dimensional hole gas, generated in the channel layer by the piezoelectric polarization of the undoped buffer layer, is used as a carrier of the channel layer.
14. A semiconductor device comprising:
an undoped buffer layer formed with an indium gallium phosphide (InGaP) semiconductor adapted to produce piezoelectric polarization; and
a channel layer stacked on the undoped buffer layer, wherein the channel layer has a thickness in a range of 30 to 150 nm,
wherein a two-dimensional hole gas, generated in the channel layer by the piezoelectric polarization of the undoped buffer layer, is used as a carrier of the channel layer.