Photocurrent noise suppression for mirror assembly
AssigneeBeijing Voyager Technology Co., Ltd.
InventorsSergio Fabien Almeida Loya, Youmin Wang
Life of this patent
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Abstract
In one example, an apparatus comprises a semiconductor integrated circuit, the semiconductor integrated circuit including a microelectromechanical system (MEMS) device layer and a silicon substrate, the MEMS layer including at least one micro-mirror assembly, the at least one micro-mirror assembly including a micro-mirror and electrodes. The at least one micro-mirror assembly further includes a light reduction layer formed below a surface of the silicon substrate. A method of fabricating the semiconductor integrated circuit is also provided.
Claims20
An apparatus comprising a light detection and ranging (LiDAR) module, the LiDAR module comprising:
- a semiconductor integrated circuit, the semiconductor integrated circuit including a microelectromechanical system (MEMS) device layer and a silicon substrate, the MEMS device layer including at least one micro-mirror assembly, the at least one micro-mirror assembly including:
- a micro-mirror comprising a reflective surface, the micro-mirror being coupled with mirror anchors on the silicon substrate at a pair of pivot points, the reflective surface being configured to reflect incident light;
- and
- electrodes coupled with electrode anchors on the silicon substrate and controllable to rotate the micro-mirror around the pair of pivot points to set a direction of reflection of the incident light by the reflective surface,
- wherein the at least one micro-mirror assembly includes a light reduction layer formed below a surface of the silicon substrate.
A method of fabricating a micro-mirror assembly of a Light Detection and Ranging (LiDAR) module, comprising:
- patterning a first silicon substrate of a silicon-on-insulator (SOI) wafer to form electrode anchors and mirror anchors, the SOI wafer comprising a first silicon substrate, a second silicon substrate, and an oxide layer sandwiched between the first silicon substrate and the second silicon substrate, the electrode anchors and mirror anchors being formed on the oxide layer;
- removing a part of the oxide layer not covered by the electrode anchors and mirror anchors to expose a part of the second silicon substrate;
- forming a light reduction layer below a surface of the exposed part of the second silicon substrate;
- bonding a silicon wafer onto the electrode anchors and the mirror anchors;
- and
- patterning the silicon wafer to form a micro-mirror and electrodes of the micro-mirror assembly on, respectively, the mirror anchors and the electrode anchors, the micro-mirror being coupled with the mirror anchors at a pair of pivot points, the electrodes being controllable to rotate the micro-mirror around the pair of pivot points.
A micro-mirror assembly fabricated by a process comprising:
- patterning a first silicon substrate of a silicon-on-insulator (SOI) wafer to form electrode anchors and mirror anchors, the SOI wafer comprising a first silicon substrate, a second silicon substrate, and an oxide layer sandwiched between the first silicon substrate and the second silicon substrate, the electrode anchors and mirror anchors being formed on the oxide layer;
- removing a part of the oxide layer not covered by the electrode anchors and mirror anchors to expose a part of the second silicon substrate;
- forming a light reduction layer below a surface of the part of the second silicon substrate;
- bonding a silicon wafer onto the electrode anchors and the mirror anchors;
- and
- patterning the silicon wafer to form a micro-mirror and electrodes of the micro-mirror assembly on, respectively, the mirror anchors and the electrode anchors, the micro-mirror being coupled with the mirror anchors at a pair of pivot points, the electrodes being controllable to rotate the micro-mirror around the pair of pivot points.
Dependencies are inferred from the claim text.