Method for manufacturing semiconductor device
First Claim
1. A method for manufacturing a semiconductor device, in which an active layer is located on a supporting substrate with an insulating intermediate layer therebetween and a movable unit included in the active layer moves in relation to the supporting substrate in response to a force applied to the movable unit, wherein the force is correlated to a dynamic quantity to be measured by the device, the method comprising steps of:
- forming an SOI substrate that includes a semiconductor substrate, an insulating layer, and a semiconductor layer such that the insulating layer is located between the semiconductor layer and the semiconductor substrate;
dry etching the semiconductor layer to form a trench that extends through the semiconductor layer to the insulating layer, wherein the dry etching is performed with a charge prevented from building up on a surface of the insulating layer that is exposed during the dry etching in order to prevent notching;
dry etching a sidewall defining the trench at a portion adjacent to a bottom of the trench to form a movable unit, wherein the later dry etching is performed with a charge building up on the surface of the insulating layer such that etching ions is strike to etch the portion of the sidewall.
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Accused Products
Abstract
A method for manufacturing a semiconductor device having a movable unit includes a step of forming an SOI substrate that includes a semiconductor substrate, an insulating layer, and a semiconductor layer such that the insulating layer is located between the semiconductor layer and the semiconductor substrate. The method further includes a step of dry etching the semiconductor layer to form a trench with a charge prevented from building up on a surface of the insulating layer that is exposed at a bottom of the trench during the dry etching. The method further includes a step of dry etching a sidewall defining the trench at a portion adjacent to the bottom of the trench to form the movable unit. The later dry etching is performed with a charge building up on the surface of the insulating layer such that etching ions strike to etch the portion of the sidewall.
24 Citations
10 Claims
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1. A method for manufacturing a semiconductor device, in which an active layer is located on a supporting substrate with an insulating intermediate layer therebetween and a movable unit included in the active layer moves in relation to the supporting substrate in response to a force applied to the movable unit, wherein the force is correlated to a dynamic quantity to be measured by the device, the method comprising steps of:
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forming an SOI substrate that includes a semiconductor substrate, an insulating layer, and a semiconductor layer such that the insulating layer is located between the semiconductor layer and the semiconductor substrate;
dry etching the semiconductor layer to form a trench that extends through the semiconductor layer to the insulating layer, wherein the dry etching is performed with a charge prevented from building up on a surface of the insulating layer that is exposed during the dry etching in order to prevent notching;
dry etching a sidewall defining the trench at a portion adjacent to a bottom of the trench to form a movable unit, wherein the later dry etching is performed with a charge building up on the surface of the insulating layer such that etching ions is strike to etch the portion of the sidewall. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for manufacturing a semiconductor device, in which an active layer is located on a supporting substrate with an insulating intermediate layer therebetween and a movable unit included in the active layer moves in relation to the supporting substrate in response to a force applied to the movable unit, wherein the movable unit includes a weight, a comb-shaped movable electrode, and a spring, wherein the force is correlated to a dynamic quantity to be measured by the device, the method comprising:
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forming an SOI substrate that includes a semiconductor substrate, an insulating layer, and a semiconductor layer such that the insulating layer is located between the semiconductor layer and the semiconductor substrate;
dry etching the semiconductor layer to form trenches that extend through the semiconductor layer to the insulating layer, wherein a charge is substantially prevented from building up on a surface of the insulating layer that is exposed during the dry etching in order to prevent notching; and
dry etching sidewalls at a portion adjacent to a bottom of each of the trenches to form a movable unit, wherein a charge builds up on the surface of the insulating layer such that etching ions strike to etch the portion of the sidewalls during the dry etching of the sidewalls, wherein the trenches include two trenches, one of which has a narrower width than the other trench for defining springs of the movable unit, wherein the dry etching of the semiconductor layer is performed until the trench having a narrower width extends to the insulating layer.
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Specification