Devices with backside metal structures and methods of formation thereof
AssigneeInfineon Technologies AG
InventorsOliver Hellmund, Ingo Muri, Johannes Baumgartl, Iris Moder, Thomas Christian Neidhart, Hans-Joachim Schulze
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Abstract
A method of fabricating a semiconductor device includes forming trenches filled with a sacrificial material. The trenches extend into a semiconductor substrate from a first side. An epitaxial layer is formed over the first side of the semiconductor substrate and the trenches. From a second side of the semiconductor substrate opposite to the first side, the sacrificial material in the trenches is removed. The trenches are filled with a conductive material.
Claims29
A method of fabricating a semiconductor device, the method comprising:
- forming trenches filled with a sacrificial material, the trenches extending into a semiconductor substrate from a first side;
- forming an epitaxial layer over the first side of the semiconductor substrate and the trenches;
- from a second side of the semiconductor substrate opposite to the first side, removing the sacrificial material in the trenches;
- and
- filling the trenches with a conductive material, wherein a top portion of each of the trenches is filled with the epitaxial layer and a bottom portion of each of the trenches is filled with the conductive material.
A method of fabricating a semiconductor device, the method comprising:
- forming trenches comprising sidewalls extending into a semiconductor substrate from a first side;
- oxidizing the trenches to form a first region of a sacrificial material;
- depositing a fill material over the first region and in the trenches to form a second region of the sacrificial material;
- etching the sacrificial material to expose a top surface of the semiconductor substrate at the first side, the etching exposing regions of the sidewalls at top portions of the trenches;
- from a second side of the semiconductor substrate opposite to the first side, removing the sacrificial material in the trenches;
- and
- filling the trenches with a conductive material.
A method of fabricating a semiconductor device, the method comprising:
- forming trenches extending into a semiconductor substrate from a first side;
- filling the trenches with a sacrificial material;
- forming a device region comprising the semiconductor device over the trenches at the first side;
- from a second side of the semiconductor substrate opposite the first side, removing the sacrificial material in the trenches;
- and
- filling the trenches with a conductive material, wherein the semiconductor device is a vertical power semiconductor device, and wherein the conductive material makes direct Ohmic contact with the vertical power semiconductor device.
A method of fabricating a semiconductor device, the method comprising:
- forming trenches filled with a sacrificial material, the trenches extending into a semiconductor substrate from a first side;
- forming a first epitaxial layer over the first side of the semiconductor substrate and the trenches;
- forming a second epitaxial layer over the first epitaxial layer;
- from a second side of the semiconductor substrate opposite to the first side, removing the sacrificial material in the trenches;
- and
- filling the trenches with a conductive material.
Dependencies are inferred from the claim text.