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:
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 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:
A semiconductor physical quantity sensor from which a stable sensor output can be obtained even when the usage environment changes. A silicon thin film is disposed on an insulating film on a supporting substrate, and a bridge structure having a weight part and moving electrodes and cantilever structures having fixed electrodes are formed as separate sections from this silicon thin film. The moving electrodes provided on the weight part and the cantilevered fixed electrodes are disposed facing each other. Slits are formed at root portions of the cantilevered fixed electrodes at the fixed ends thereof, and the width W1 of the root portions is thereby made narrower than the width W2 of the fixed electrodes proper. As a result, the transmission of warp of the supporting substrate to the cantilevered fixed electrodes is suppressed.
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:
An etching method for a silicon substrate, which can easily smooth the etching surface of the (110)-oriented silicon, is disclosed. A container is filled with KOH solution. In the KOH solution is immersed a (110)-oriented silicon wafer having a PN junction and is also disposed a platinum electrode plate to face the silicon wafer. To between a platinum electrode of the silicon wafer and the platinum electrode plate are connected a constant voltage power source, an ammeter and a contact in series. A controller starts etching from one surface on which the PN junction is formed, and terminates voltage application when the specified time lapses after the formation of an anodic oxide film is equilibrated with the etching of the anodic oxide film on the etching surface on the PN junction part. In this case, the controller detects flowing current through the ammeter, and the point of time when the equilibrium state is obtained is the point of inflection of the detected current to the constant current after the peak thereof.
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 physical quantity sensor includes a substrate, a beam-structure movable portion and a fixed portion. The beam-structure movable portion is suspended by four anchors formed of polycrystalline films. A rectangular mass is suspended between beams. Movable electrodes project from both sides of the mass. First fixed electrodes and second fixed electrodes are fixedly provided on the surface of the substrate. The substrate has a laminated structure, wherein an oxide film, attaching film, insulating films, conductive film and insulating film are laminated on the substrate. An anchor formed from the conductive film is electrically connected to the attaching film. An electrode pad made of an aluminum film is provided the above the anchor. Because this structure enables the potential of the attaching film to be fixed, parasitic capacitance can be decreased.