Needle Cell Trench MOSFET
AssigneeInfineon Technologies Austria AG
InventorsChristof Altstaetter, Marcel Rene Mueller, Oliver Blank, David Laforet
Life of this patent
Estimating the term…
Abstract
A power semiconductor die has a semiconductor body coupled to first and second load terminals, and at least one power cell. In a horizontal cross-section of the at least one power cell, a contact has a contact region which horizontally overlaps with a field plate electrode and horizontally protrudes from the field plate trench, and a recess region does not horizontally overlap with the contact region and extends into a horizontal circumference of the field plate trench.
Claims22
A power semiconductor die having a semiconductor body coupled to a first load terminal and a second load terminal of the power semiconductor die and configured to conduct a load current between the first and second load terminals, the power semiconductor die comprising at least one power cell having:
- as a respective part of the semiconductor body, a section of a drift zone of a first conductivity type, a section of a channel zone of a second conductivity type and a section of a source zone of the first conductivity type, the channel zone section being electrically connected to the first load terminal and isolating the source zone section from the drift zone section;
- a columnar field plate trench extending into the semiconductor body along a vertical direction, the columnar field plate trench including a field plate electrode and a field insulator, the field insulator forming a field plate trench sidewall of the columnar field plate trench;
- a control trench structure configured to control the load current, the control trench structure extending into the semiconductor body along the vertical direction and surrounding the columnar field plate trench, the control trench structure including at least one control electrode section and a control trench insulator, the control trench insulator forming control trench sidewalls of the control trench structure;
- and
- a contact configured to establish an electrical connection between the first load terminal and each of the channel zone section, the source zone section and the field plate electrode,
- wherein in a horizontal cross-section of the at least one power cell:
- the contact has a contact region horizontally overlapping with the field plate electrode and horizontally protruding from the field plate trench;
- and
- a recess region not horizontally overlapping with the contact region and extending into a horizontal circumference of the field plate trench.
A method of processing a power semiconductor die, the method comprising:
- providing a semiconductor body to be coupled to a first load terminal and a second load terminal of the power semiconductor die and configured to conduct a load current between the load terminals;
- and
- forming at least one power cell having:
- as a respective part of the semiconductor body, a section of a drift zone of a first conductivity type, a section of a channel zone of a second conductivity type and a section of a source zone of the first conductivity type, the channel zone section being electrically connected to the first load terminal and isolating the source zone section from the drift zone section;
- a columnar field plate trench extending into the semiconductor body along the vertical direction, the columnar field plate trench including a field plate electrode and a field insulator, the field insulator forming a field plate trench sidewall of the columnar field plate trench;
- a control trench structure configured to control the load current, the control trench structure extending into the semiconductor body along the vertical direction and surrounding the columnar field plate trench, the control trench structure including at least one control electrode section and a control trench insulator, the control trench insulator forming control trench sidewalls of the control trench structure:
- a contact configured to establish an electrical connection between the first load terminal and each of the channel zone section, the source zone section and the field plate electrode,
- wherein in a horizontal cross-section of the at least one power cell:
- the contact has a contact region horizontally overlapping with the field plate electrode and horizontally protruding from the field plate trench;
- and
- a recess region horizontally not overlapping with the contact region and extending into a horizontal circumference of the field plate trench.
Dependencies are inferred from the claim text.