Trenched Faraday shielding

A device comprising:

• a semiconductor substrate having a surface with a trench;
• first and second conduction terminals supported by the semiconductor substrate;
• a control electrode supported by the semiconductor substrate between the first and second conduction terminals and configured to control flow of charge carriers during operation between the first and second conduction terminals;
• and
• a Faraday shield supported by the semiconductor substrate and disposed between the control electrode and the second conduction terminal;
• wherein the trench is laterally spaced from the control electrode by a lateral spacing,
• wherein the Faraday shield comprises a first portion that extends laterally above the surface of the semiconductor substrate across the lateral spacing and a second portion that extends laterally in the trench,
• wherein the Faraday shield is not electrically connected to the control electrode, and
• wherein the second portion of the Faraday shield extends laterally in parallel with a bottom of the trench, and wherein the second portion of the Faraday shield extends less than an entire lateral extent of the trench.

A device comprising:

• a semiconductor substrate having a surface with a trench;
• first and second conduction terminals supported by the semiconductor substrate;
• a control electrode supported by the semiconductor substrate between the first and second conduction terminals and configured to control flow of charge carriers during operation between the first and second conduction terminals;
• and
• a Faraday shield supported by the semiconductor substrate and disposed between the control electrode and the second conduction terminal;
• wherein the trench is laterally spaced from the control electrode by a lateral spacing,
• wherein the Faraday shield comprises a first portion that extends laterally above the surface of the semiconductor substrate across the lateral spacing and a second portion that extends laterally in the trench,
• wherein the Faraday shield is not electrically connected to the control electrode, and
• wherein the trench is spaced from the second conduction terminal such that the trench is closer to the control electrode than to the second conduction terminal.

An electronic apparatus comprising:

• a semiconductor substrate having a surface with a trench;
• and
• a transistor structure comprising a transistor body region disposed in the semiconductor substrate, the transistor structure further comprising:
• source and drain terminals supported by the semiconductor substrate;
• a gate structure supported by the semiconductor substrate between the source and drain terminals and configured to control current flow during operation between the source and drain terminals through the transistor body region;
• and
• a shield plate disposed between the gate structure and the drain terminal;
• wherein the trench is laterally spaced from the gate structure by a lateral spacing,
• wherein the shield plate comprises a first portion that extends laterally above the surface of the semiconductor substrate across the lateral spacing and a second portion that extends laterally in the trench at a height lower than the gate structure,
• wherein the shield plate is plate-shaped such that the second portion has upper and lower surfaces that conform to a topography of the trench, and
• wherein the shield plate is not electrically connected to the gate structure.

A method of fabricating a transistor, the method comprising:

• forming a control electrode of the transistor on a surface of a semiconductor substrate;
• implanting dopant in the semiconductor substrate to form first and second conduction terminal regions at the surface of the semiconductor substrate, the first conduction terminal region being adjacent to the control electrode, and the second conduction terminal region being spaced from the control electrode;
• etching a trench in the surface of the semiconductor substrate, wherein the trench is laterally spaced from the control electrode by a lateral spacing;
• forming a Faraday shield on the surface of the semiconductor substrate, wherein the Faraday shield comprises a first portion that extends laterally above the surface of the semiconductor substrate across the lateral spacing and a second portion that extends laterally in the trench at a height lower than the control electrode, and wherein the Faraday shield is plate-shaped such that the second portion has upper and lower surfaces that conform to a topography of the trench;
• and
• depositing a dielectric layer between the Faraday shield and the control electrode such that the Faraday shield is not electrically connected to the control electrode.

A method of fabricating a transistor, the method comprising:

• forming a control electrode of the transistor on a surface of a semiconductor substrate;
• implanting dopant in the semiconductor substrate to form first and second conduction terminal regions at the surface of the semiconductor substrate, the first conduction terminal region being adjacent to the control electrode, and the second conduction terminal region being spaced from the control electrode;
• etching a trench in the surface of the semiconductor substrate, wherein the trench is laterally spaced from the control electrode by a lateral spacing;
• forming a Faraday shield on the surface of the semiconductor substrate, wherein the Faraday shield comprises a first portion that extends laterally above the surface of the semiconductor substrate across the lateral spacing and a second portion that extends laterally in the trench at a height lower than the control electrode;
• and
• depositing a dielectric layer between the Faraday shield and the control electrode such that the Faraday shield is not electrically connected to the control electrode;
• wherein the trench is spaced from the second conduction terminal region such that the trench is closer to the control electrode than to the second conduction terminal region.