摘要:
In a method for manufacturing a semiconductor acceleration sensor, a movable portion including a mass portion and movable electrodes is formed in a single crystal silicon thin film provided on a silicon wafer through an insulation film by etching both the single crystal silicon thin film and the silicon wafer. In this case, the movable portion is finally defined at a movable portion defining step that is carried out in a vapor phase atmosphere. Accordingly, the movable portion is prevented from sticking to other regions due to etchant during the manufacture thereof.
摘要:
A semiconductor accelerometer device is formed on an SOI substrate by micro-machining. A movable unit is supported at both ends, and a weight portion is movable in response to acceleration exerted in the detection direction. A movable electrode is formed in a comb shape integrally with the weight portion. A pair of fixed electrodes in a comb shape are cantilevered and interleaved with the movable electrode to face the movable electrode. A plurality of through holes is provided in the electrodes so that the electrodes have Rahmen structure which is a series of rectangular frames. This structure reduces the weight of each electrode while increasing the strength against twist force. The electrodes are less likely from breaking in response to an acceleration exerted in a direction perpendicular to the normal detection direction because of reduced weight.
摘要:
A semiconductor dynamic quantity sensor includes a semiconductor support substrate having a specific resistance equal to or less than 3&OHgr; cm. An insulation film is provided on the support substrate and a semiconductor layer is provided on the support substrate with the insulation film interposed therebetween. The semiconductor layer has a specific resistance equal to or less than 3&OHgr; cm. A movable electrode is provided in the semiconductor layer to be displaced according to a dynamic quantity acting thereto. A fixed electrode is fixedly provided in the semiconductor layer to make a specific gap with the movable electrode and to from a capacitor with the movable electrode. The capacitor has a capacity that changes in response to displacement of the movable electrode to detect the dynamic quantity.
摘要:
A method of manufacturing a semiconductor device is provided. The device is manufactured with use of an SOI (Silicon On Insulator) substrate having a first silicon layer, an oxide layer, and a second silicon layer laminated in this order. After forming a trench reaching the oxide layer from the second silicon layer, dry etching is performed, thus allowing the oxide layer located at the trench bottom to be charged at first. This charging forces etching ions to impinge upon part of the second silicon layer located laterally to the trench bottom. Such part is removed, forming a movable section. For example, ions to neutralize the electric charges are administered into the trench, so that the electric charges are removed from charged movable electrodes and their charged surrounding regions. Removing the electric charges prevents the movable section to stick to its surrounding portions.
摘要:
A method for manufacturing a semiconductor device having a movable portion includes the steps of: forming a trench on a semiconductor layer so that the trench reaches an insulation layer; and forming a movable portion by etching a sidewall of the trench so that the semiconductor layer is separated from the insulation layer. The steps of forming the trench and forming the movable portion are performed by a reactive ion etching method. The insulation layer disposed on the bottom of the trench is prevented from charging positively in the step of forming the trench. The insulation layer disposed on the bottom of the trench is charged positively in the step of forming the movable portion.
摘要:
A method of manufacturing a semiconductor device is provided. The device is manufactured with use of an SOI (Silicon On Insulator) substrate having a first silicon layer, an oxide layer, and a second silicon layer laminated in this order. After forming a trench reaching the oxide layer from the second silicon layer, dry etching is performed, thus allowing the oxide layer located at the trench bottom to be charged at first. This charging forces etching ions to impinge upon part of the second silicon layer located laterally to the trench bottom. Such part is removed, forming a movable section. For example, ions to neutralize the electric charges are administered into the trench, so that the electric charges are removed from charged movable electrodes and their charged surrounding regions. Removing the electric charges prevents the movable section to stick to its surrounding portions.
摘要:
A method for manufacturing a semiconductor device having a movable portion includes the steps of: forming a trench on a semiconductor layer so that the trench reaches an insulation layer; and forming a movable portion by etching a sidewall of the trench so that the semiconductor layer is separated from the insulation layer. The steps of forming the trench and forming the movable portion are performed by a reactive ion etching method. The insulation layer disposed on the bottom of the trench is prevented from charging positively in the step of forming the trench. The insulation layer disposed on the bottom of the trench is charged positively in the step of forming the movable portion.
摘要:
A semiconductor acceleration sensor, which prevents an adhesion of a movable portion to a fixed portion due to an electrostatic force generated during being handled. The acceleration sensor has a sensor portion and a handling portion. The sensor portion has a first semiconductor layer; a movable portion including a weight portion supported to the first semiconductor layer for moving in accordance with an acceleration externally applied thereto and movable electrodes integrally formed with the weight portion; and fixed electrodes having a detection surface confronted to a detection surface of the movable electrodes and supported to the first semiconductor layer. The handling portion is to be contacted during being handled, and is provided at surrounding portion of the sensor portion with a trench interposed therebetween. The sensor portion is electrically insulated from the handling portion by the trench.
摘要:
A semiconductor acceleration sensor capable of reducing a leakage current and manufacturing method thereof is disclosed. A beam structure is disposed on a silicon substrate. The beam structure has a movable section, and the movable section is disposed spaced at a prescribed distance above silicon substrate. A movable electrode section is formed in one portion of movable section. Fixed electrodes made of an impurity diffusion layer are formed in silicon substrate to correspond to both sides of a movable electrode section. A peripheral circuit is formed in silicon substrate. The beam structure and the peripheral circuit are electrically connected by an electroconductive thin film, made of polysilicon. Then, when a voltage is applied to the beam structure, and a voltage is applied to both fixed electrodes, an inversion layer is formed, and an electrical current flows between the fixed electrodes. In the case where an acceleration is received and movable section is displaced, the electrical current flowing between the fixed electrodes changes.
摘要:
A semiconductor acceleration sensor according to the present invention performs acceleration detection by means of detecting increase or decrease in electrical current flowing between fixed electrodes formed on a semiconductor substrate taking a movable section in a movable state supported on the semiconductor substrate as a gate electrode. Two transistor structures are utilized in this detection. Current between fixed electrodes in one transistor structure increases when the movable section is subjected to acceleration and is displaced. At that time, current between fixed electrodes in the other transistor structure decreases. These two transistor structures are disposed proximately. By means of this proximate disposition, fluctuations in characteristics of both transistors are reduced, and by means of acceleration detection by differential type, temperature characteristics of the two transistors can be canceled favorably.