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 manufacturing method, comprising:
forming a base portion with a compound semiconductor;
forming, on the base portion, a buffer layer that lattice-matches the compound semiconductor of the base portion and produces piezoelectric polarization;
forming, on the buffer layer, a channel layer that lattice-matches the buffer layer and produces a two-dimensional hole gas by the piezoelectric polarization of the buffer layer, wherein the channel layer is an undoped layer;
forming a gate on the channel layer; and
forming a drain and a source on the channel layer, wherein the gate is between the drain and the source, and wherein each of the drain and the source are stacked on the channel layer.
2. The semiconductor device manufacturing method of claim 1 , wherein the buffer layer is an epitaxially grown InGaP layer.
3. The semiconductor device manufacturing method of claim 1 , wherein the buffer layer is an epitaxially grown undoped InGaP layer.
4. The semiconductor device manufacturing method of claim 1 , wherein the channel layer is a GaAs layer which is epitaxially grown on the buffer layer.
5. The semiconductor device manufacturing method of claim 1 , wherein the gate is an n-type gate layer.
6. The semiconductor device manufacturing method of claim 5 , further comprising:
forming, on the channel layer, an n-type first gate layer by epitaxially growing an InGaP layer with an n-type impurity; and
forming, on the n-type first gate layer, an n-type second gate layer by epitaxially growing a GaAs layer with the n-type impurity,
wherein the n-type gate layer comprises the n-type first gate layer and the n-type second gate layer.
7. The semiconductor device manufacturing method of claim 6 , wherein a concentration of the n-type impurity in each of the n-type first gate layer and the n-type second gate layer is in a range of 1×10 17 atoms/cm 3 to 5×10 19 atoms/cm 3 .
8. The semiconductor device manufacturing method of claim 1 , wherein the buffer layer comprises a plurality of semiconductor layers.
9. A semiconductor device manufacturing method, comprising:
forming a base portion with a compound semiconductor;
forming, on the base portion, a buffer layer that lattice-matches the compound semiconductor of the base portion and produces piezoelectric polarization, wherein the buffer layer comprises a plurality of semiconductor layers;
forming, on the buffer layer, a channel layer that lattice-matches the buffer layer and produces a two-dimensional hole gas by the piezoelectric polarization of the buffer layer;
forming a gate on the channel layer; and
forming a drain and a source on the channel layer, wherein the gate is between the drain and the source, and wherein each of the drain and the source are stacked on the channel layer.