The dielectric-base transistor (DBT) is expected to be coupled with various functional oxides such as high-temperature superconductors and ferroelectrics. We experimented with lowering the conduction band of the channel to reduce the operating voltage.LaTiO3deposited onSrTiO3supplies carriers in theSrTiO3substrate by displacingSr2+andLa3+.With this technique, we fabricated aYBa2Cu3O7−x/In2O3/SrTiO3/LaTiO3/SrTiO3transistor with a partially doped channel. The transistor operates at under 1 V while maintaining a voltage amplification factor of 2, which is one order smaller than the 15 V operating voltage of a transistor with an undoped channel. The base potential relative to the emitter conduction band has been reduced to 0.3 eV. ©1997 American Institute of Physics.