Semiconductor dynamic quantity detecting sensor and manufacturing method of the same
AssigneesNippon Soken, Inc., Denso Corporation
InventorsTakeshi Ito, Kazushi Asami, Tsuyoshi Fukada, Hirofumi Higuchi
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Abstract
A semiconductor dynamic quantity sensor, for example, an acceleration sensor is formed on a SOI substrate having an activation layer and a supporting layer with an oxide film interposed therebetween. A structure for the sensor is formed in the activation layer. An opening is formed in the supporting layer and the oxide film to expose the structure. In this sensor, stress layer is formed in the activation layer at a side contacting the oxide film. The stress layer is removed at a region facing the opening to prevent the structure from cambering.
Claims13
A method for manufacturing a semiconductor dynamic quantity sensor, comprising steps of:
- providing a laminated semiconductor substrate in which a first semiconductor layer is laminated on a second semiconductor layer with an oxide film interposed therebetween, the first semiconductor layer being thinner than the second semiconductor layer;
- forming a movable structure in the first semiconductor layer, the movable structure having a back surface and being movable in accordance with a dynamic quantity applied thereto;
- forming an opening in the second substrate and the oxide film by removing a portion of the second semiconductor layer and the oxide film that is located under the movable structure;
- and
- removing a portion of the back surface of the movable structure formed in the first semiconductor layer, the portion facing the opening and including oxygen that causes stress to the movable structure.
A method for manufacturing a semiconductor dynamic quantity sensor, comprising steps of:
- providing a semiconductor substrate including a first semiconductor layer, a second semiconductor layer and an oxide film interposed between the first and second semiconductor layers, the first semiconductor layer being thinner than the second semiconductor layer;
- forming a movable structure in the first semiconductor layer, the movable structure having a back surface and being movable in accordance with a dynamic quantity applied thereto;
- forming an opening in the second substrate and the oxide film by removing a portion of the second semiconductor layer and the oxide film that is located under the movable structure;
- and
- removing a portion of the back surface of the movable structure formed in the first semiconductor layer, the portion facing the opening and including oxygen.
A semiconductor dynamic quantity sensor comprising:
- a semiconductor substrate having a first semiconductor layer, a second semiconductor layer, and an oxide film interposed between the first and second semiconductor layers, wherein the first semiconductor layer has a back surface close to the oxide film and has a thickness less than that of the second semiconductor layer;
- an oxygen including layer disposed between the oxide film and the first semiconductor layer;
- and
- a structure farmed in the first semiconductor layer above an opening which is formed in the second semiconductor layer, the structure detecting dynamic quantity that is applied thereto, wherein
- the oxygen including layer contacts the back surface of the first semiconductor layer while the oxygen including layer is removed at a region where the opening is located so that a portion of the back surface of the first semiconductor layer is exposed to the opening.
Dependencies are inferred from the claim text.