摘要:
A method for fabricating a semiconductor sensor wherein deflection of a movable member is disclosed. A silicon oxide film is formed on a silicon substrate, and a movable member composed of polycrystalline silicon is formed on the silicon oxide film by means of a low-pressured chemical vapor deposition process. At this time, silane is caused to flow into an oven, and the supply of silane is stopped when a layer of polycrystalline silicon has been deposited on the silicon substrate, and a first polycrystalline silicon layer is formed. By means of stopping the supply of silane, a silicon oxide layer of a thickness of several angstroms to several tens of angstroms is formed on the first polycrystalline silicon layer by atmosphere O.sub.2. A second polycrystalline silicon layer of a thickness of 1 .mu.m is formed on the silicon oxide layer by means of causing silane to flow into the oven. Patterning by dry etching or the like through a photo-lithographic process is performed to form a movable member. The silicon oxide film below the movable member is then etched.
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.
摘要:
A semiconductor sensor including a movable member beam structure having a reduced deflection characteristic. The sensor includes a movable beam structure film suspended from a semiconductor substrate, with a gap interposed between the beam structure film and the substrate. The beam structure film is composed of a plurality of film layers that are laminated in a direction of film thickness. Further, a stress relieving layer is interposed between respective films to reduce overall internal stress on the structure.
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:
It is an object to provide a method of fabrication for a semiconductor acceleration sensor which can prevent destruction of a movable portion during dicing. A sacrificial layer composed of silicon oxide film is formed on a silicon substrate, and a movable member composed of polycrystalline silicon is formed on the sacrificial layer. A polyimide film is applied on the movable member at room temperature and heated to approximately 350.degree. C. to harden. The movable member is supported by this polyimide film. Accordingly, etching liquid penetration holes are formed on the polyimide film. Further, the sacrificial layer disposed between the movable member and the silicon substrate is etched away by means of dipping the silicon substrate into hydrofluoric acid-based etching liquid. Thereafter, the silicon substrate is dipped into demineralized water to replace the etching liquid with demineralized water, and subsequently the silicon substrate is dried. Accordingly, the silicon substrate is diced and thereafter the polyimide film is etched away by O.sub.2 ashing.
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 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 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 semiconductor sensor has gauge resistors. The gauge resistors connect with aluminum electrodes through contact holes, and form a bridge circuit. The gauge resistors are formed on each chip area of a semiconductor substrate before dicing the chip areas. Then, the resistances of the gauge resistors or the output of the bridge circuit are measured. Contact positions of the gauge resistors or the size and/or shape of the contact holes are adjusted based on the result of the measurement in order to adjust the offset voltage of the bridge circuit formed on each chip area.
摘要:
A method of manufacturing a magneto-electric conversion device having a large rate of change of magnetic resistance and which is easy to position with respect to a magnetized surface, and a moving subject displacement detector using a magneto-electric conversion device manufactured by that method. A magnet which rotates together with the rotation of a drive gear is magnetized in alternately differing north and south poles, arranged in an equal sized section from a center portion thereof. An IC chip is positioned opposite to and at a distance from the magnetized surface of the magnet. Magneto-electric conversion devices are located on the IC chip. These magneto-electric conversion devices are formed by repeated alternate depositions, onto a surface of a single-crystal silicon substrate, of magnetic cobalt films having a thickness of several to several tens of angstroms and non-magnetic copper films having a thickness of several to several tens of angstroms.