I claim:
1. A field-effect transistor, comprising:
a semiconductor substrate;
a source electrode and a drain electrode formed in said semiconductor substrate;
an inversion channel formed in said semiconductor substrate between said source electrode and said drain electrode, said inversion channel having a given energy interval for controlling a charge carrier density in said inversion channel;
a gate electrode disposed between said source electrode and said drain electrode and fabricated from a material having no energetically permitted state in a range of the given energy interval; and
an insulation layer separating said gate electrode from said inversion channel.
2. The field-effect transistor according to claim 1, wherein said gate electrode is formed from a material with a crystalline structure, and said material has a band gap in the given energy interval.
3. The field-effect transistor according to claim 2, wherein the band gap of said gate electrode comprises an energy level of a basic state of the charge carriers in said inversion channel between said source electrode and said drain electrode.
4. The field-effect transistor according to claim 1, wherein said gate electrode is formed of a material having a band gap in an electronic band structure in an energy range of up to 2 eV above the Fermi level.
5. The field-effect transistor according to claim 4, wherein said semiconductor substrate is a silicon semiconductor substrate, and said gate electrode is formed of 2HTaS2.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A high frequency surgical device for generating high frequency energy for separating andor coagulating of biological tissue, comprising at least one energy source and at least one output socket, into which a longitudinally extending electrically conductive plug contact of an electrosurgical instrument can be inserted, and which output socket comprises a catch for engaging an opposite catch configured in the plug contact, wherein a socket contact is electrically insulated from the catch, which socket contact is electrically connected to the energy source.
2. A high frequency surgical device according to claim 1, wherein a maximum possible distance from a contact point at the plug contact to an outside of the high frequency surgical device is greater for the socket contact than for the catch.
3. A high frequency surgical device according to claim 1, wherein the socket contact is disposed so that it contacts the plug contact in an inserted state at a distal end of the plug contact.
4. A high frequency surgical device according to claim 1, wherein the socket contact is disposed, so that it only contacts the plug contact during insertion after the catch has substantially completely engaged the opposite catch.
5. A high frequency surgical device according to claim 1, wherein the socket contact is made of a spring elastic material and disposed so it can be elastically displaced by the plug in contact in inserted state.
6. A high frequency surgical device according to claim 4, wherein the catch is made of a spring elastic material, wherein the spring constant of the catch is greater than the spring constant of the socket contact.
7. A high frequency surgical device according to claim 1, wherein the socket contact is configured substantially fork shaped or slotted and disposed, so that the axis of the rotation symmetrical plug contact is recessed in the plug contact.
8. A high frequency surgical device according to claim 1, wherein the output socket is configured to receive a single pole round plug, in particular a Bovie plug or an Olympus 6 mm round plug.
9. A high frequency surgical device according to claim 2, wherein the socket contact is disposed so that it contacts the plug contact in an inserted state at a distal end of the plug contact.