Abstract:
The present disclosure pertains to our discovery of a particularly efficient method for etching a multi-part cavity in a substrate. The method provides for first etching a shaped opening, depositing a protective layer over at least a portion of the inner surface of the shaped opening, and then etching a shaped cavity directly beneath and in continuous communication with the shaped opening. The protective layer protects the etch profile of the shaped opening during etching of the shaped cavity, so that the shaped opening and the shaped cavity can be etched to have different shapes, if desired. In particular embodiments of the method of the invention, lateral etch barrier layers and/or implanted etch stops are also used to direct the etching process. The method of the invention can be applied to any application where it is necessary or desirable to provide a shaped opening and an underlying shaped cavity having varying shapes. The method is also useful whenever it is necessary to maintain tight control over the dimensions of the shaped opening.
Abstract:
A layer system with a silicon layer (11) is disclosed, on which a surface passivation layer (17) is at least partly applied. The passivation layer (17) comprises a first at least extensively inorganic partial layer (14) and a second at least extensively polymeric partial layer (15). A method for production of a passivation layer (17) on a silicon layer (11) is also disclosed, whereby a first inorganic partial layer (14) is applied to the silicon layer (11), an intermediate layer applied to the above and on the intermediate layer a second polymeric partial layer (15) is applied to form the passivation layer (17). The production of the intermediate layer is achieved, whereby in the surface region thereof adjacent to the first partial layer (14), the composition thereof is the same as the first partial layer (14) and in the surface region thereof adjacent to the second partial layer (15) the composition thereof is the same as the second partial layer (15) and that the composition of the intermediate layer varies continuously or stepwise from the composition corresponding to the first partial layer to the composition corresponding to the second partial layer. The disclosed layer system or the disclosed method are particularly suitable for the production of self-supporting structures in silicon.
Abstract:
A thin silicon-rich nitride film (e.g., having a thickness in the range of around 100A to 10000A) deposited using low-pressure chemical vapor deposition (LPCVD) is used for etch stop during vapor HF etching in various MEMS wafer fabrication processes and devices. The LPCVD silicon-rich nitride film may replace, or be used in combination with, a LPCVD stoichiometric nitride layer in many existing MEMS fabrication processes and devices. The LPCVD silicon-rich nitride film is deposited at high temperatures (e.g., typically around 650-900 degrees C). Such a LPCVD silicon-rich nitride film generally has enhanced etch selectivity to vapor HF and other harsh chemical environments compared to stoichiometric silicon nitride and therefore a thinner layer typically can be used as an embedded etch stop layer in various MEMS wafer fabrication processes and devices and particularly for vapor HF etching processes, saving time and money in the fabrication process.
Abstract:
Es wird ein Schichtsystem mit einer Siliziumschicht (11) vorgeschlagen, auf der zumindest bereichsweise oberflächlich eine Passivierschicht (17) aufgebracht ist, wobei die Passivierschicht (17) eine erste, zumindest weitgehend anorganische Teilschicht (14) und eine zweite, zumindest weitgehend polymere Teilschicht (15) aufweist. Weiter wird ein Verfahren zur Erzeugung einer Passivierschicht (17) auf einer Siliziumschicht (11) vor geschlagen, wobei auf der Siliziumschicht (11) eine erste, anorganische Teilschicht (14), auf dieser eine Zwischenschicht und auf dieser eine zweite, polymere Teilschicht (15) erzeugt wird, die die Passivierschicht (17) bilden. Die Erzeugung der Zwischenschicht erfolgt derart, dass die Zwischenschicht in ihrem der ersten Teilschicht (14) benachbarten Oberflächenbereich wie die erste Teilschicht (14) und in ihrem der zweiten Teilschicht (15) benachbarten Oberflächenbereich wie die zweite Teilschicht (15) zusammengesetzt ist, und dass die Zusammensetzung der Zwischenschicht kontinuierlich oder stufenweise von der Zusammensetzung entsprechend der ersten Teilschicht in die Zusammensetzung entsprechend der zweiten Teilschicht übergeht. Das vorgeschlagene Schichtsystem oder das vorgeschlagene Verfahren eignet sich besonders bei der Erzeugung von freitragenden Strukturen in Silizium.
Abstract:
A semiconductor device composed of a capacitive humidity sensor comprised of a moisture-sensitive polymer layer electrografted to an electrically conductive metal layer situated on an CMOS substrate or a combined MEMS and CMOS substrate, and exposed within an opening through a passivation layer, packages composed of the encapsulated device, and methods of forming the capacitive humidity sensor within the semiconductor device, are provided.
Abstract:
A technique for manufacturing a piezoresistive sensing structure (170) includes a number of process steps. Initially, a piezoresistive element (108) is implanted into a first side of an assembly (102,106,104A) that includes a semiconductor material (102,104A). A passivation layer (110A) is then formed on the first side of the assembly (102,106,104A) over the element (108). The passivation layer (110A) is then removed from selected areas on the first side of the assembly (102,106,104A). A first mask is then provided on the passivation layer (110A) in a desired pattern. A beam (152), which includes the element (108), is then formed in the assembly over at least a portion of the assembly (102,106,104A) that is to provide a cavity (103). The passivation layer (110A) provides a second mask, in the formation of the beam (152), that determines a width of the formed beam (152).