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:
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 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 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:
Plural semiconductor chips such as acceleration sensor chips formed on the first surface of a substrate are separated into individual pieces by dicing the substrate from the second surface thereof. A groove surrounding each sensor chip, along which the sensor chip is diced out, is formed at the same time the sensor chip is formed on the first surface. Before dicing, a protecting sheet covering the first surface is pasted along the sidewalls and the bottom wall of the groove. The groove is made sufficiently wide to ensure that the protecting sheet is bent along the walls of the groove without leaving a space between the groove and the protecting sheet. Thus, dicing dusts generated in the dicing process are prevented from being scattered and entering the sensor chip.
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 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:
In the present invention, a first protective layer formed over a diaphragm is prevented from being etched unnecessarily at the time of etching a second protective layer, and the detection accuracy of the diaphragm is improved.In a process for producing a semiconductor pressure sensor, a first protective layer 4, a metal layer 8 and a second protective layer 6 are successively formed by deposition over a diaphragm 1a, and the second protective layer 6 is removed by etching so that the second protective layer 6 is left on a predetermined portion of an electrode 5. Since the metal layer 8 acts as an etching stopper layer at the time of removing the second protective layer 6 by etching, the first protective layer 4 over the diaphragm 1a is prevented from being etched. The metal layer 8 is removed by etching thereafter so that only the first protective layer 4 is formed over the diaphragm 1a.
摘要:
It is intended to provide an etching method for semiconductor devices in which the etching depth or the thickness of a thin thickness portion can be precisely controlled. According to experiment results, when a P-type substrate in which an N-type epitaxial layer is formed is immersed in an etching solution such as KOH or the like, and a voltage for reverse bias of PN junction is applied between an electrode plate opposing the substrate and the epitaxial layer to perform electrochemical etching, it has been found that the distance from the PN junction plane to the etching stop position is approximately equal to a depletion layer width at the substrate side of the PN junction portion. Namely, the etching stops at the forward end of the depletion layer. Therefore, the junction depletion layer width at the substrate side is controlled to be a size obtained by subtracting a necessary depth for etching from a thickness of the semiconductor substrate except for the semiconductor layer, so that the etching depth or the thickness of the thin thickness portion remaining after etching can be precisely controlled.
摘要:
An acceleration sensor has a ring-shaped movable electrode connected to an anchor part via beams and a fixed electrode facing the ring-shaped movable electrode defining a specific interval, which are disposed on a substrate. The movable electrode is displaced by acceleration approximately in parallel to the substrate and contacts the fixed electrode, so that the acceleration is detected. The fixed electrode is divided into a detecting fixed electrode for contacting the movable electrode and a sensitivity controlling fixed electrode insulated from the detecting fixed electrode. Accordingly, potential differences between the movable electrode and the detecting fixed electrode and between the movable electrode and the sensitivity controlling fixed electrode are independently controlled to control sensitivity of acceleration.