Abstract:
A process for etching semiconductor substrates using a deep reactive ion etching process to produce through holes or slots (hereinafter “slots”) in the substrates. The process includes applying a first layer to a back side of a substrate as a first etch stop material. The first layer is a relatively soft etch stop material. A second layer is applied to the first layer on the back side of the substrate to provide a composite etch stop layer. The second layer is a relatively hard etch stop material. The substrate is etched from a side opposite the back side of the substrate to provide a slot in the substrate.
Abstract:
Processes for the removal of a layer or region from a workpiece material by contact with a process gas in the manufacture of a microstructure are enhanced by the ability to accurately determine the endpoint of the removal step. A vapor phase etchant is used to remove a material that has been deposited on a substrate, with or without other deposited structure thereon. By creating an impedance at the exit of an etching chamber (or downstream thereof), as the vapor phase etchant passes from the etching chamber, a gaseous product of the etching reaction is monitored; and the endpoint of the removal process can be determined. The vapor phase etching process can be flow through, a combination of flow through and pulse, or recirculated back to the etching chamber
Abstract:
A technique for manufacturing a micro-electro-mechanical (MEM) structure includes a number of steps. Initially, a substrate is provided. Next, a plurality of trenches are etched into the substrate with a first etch. Then, a charging layer is formed at a bottom of each of the trenches to form undercut trenches. Finally, a second etch is provided into the undercut trenches. The charging layer causes the second etch to laterally etch foots in the substrate between the undercut trenches. The footers undercut the substrate to release a portion of the substrate for providing a movable structure between the undercut trenches and above the footers.
Abstract:
Processes for the removal of a layer or region from a workpiece material by contact with a process gas in the manufacture of a microstructure are enhanced by the ability to accurately determine the endpoint of the removal step. A vapor phase etchant is used to remove a material that has been deposited on a substrate, with or without other deposited structure thereon. By creating an impedance at the exit of an etching chamber (or downstream thereof), as the vapor phase etchant passes from the etching chamber, a gaseous product of the etching reaction is monitored, and the endpoint of the removal process can be determined. The vapor phase etching process can be flow through, a combination of flow through and pulse, or recirculated back to the etching chamber.
Abstract:
A process for making a microelectromechanical device having a moveable component defined by a gap pattern in a semiconductor layer of a silicon-on-insulator wafer involves the use of a plurality of deep reactive ion etching steps at various etch depths that are used to allow a buried oxide layer of the silicon-on-insulator wafer to be exposed in selected areas before the entire moveable component of the resulting device is freed for movement. This method allows wet release techniques to be used to remove the buried oxide layer without developing stiction problems. This is achieved by utilizing deep reactive ion etching to free the moveable component after a selected portion of the buried oxide layer has been removed by wet etching.
Abstract:
A process for forming a microelectromechanical system (MEMS) device by a deep reactive ion etching (DRIE) process during which a substrate overlying a cavity is etched to form trenches that breach the cavity to delineate suspended structures. A first general feature of the process is to define suspended structures with a DRIE process, such that the dimensions desired for the suspended structures are obtained. A second general feature is the proper location of specialized features, such as stiction bumps, vulnerable to erosion caused by the DRIE process. Yet another general feature is to control the environment surrounding suspended structures delineated by DRIE in order to obtain their desired dimensions. A significant problem identified and solved by the invention is the propensity for the DRIE process to etch certain suspended features at different rates. In addition to etching wider trenches more rapidly than narrower trenches, the DRIE process erodes suspended structures more rapidly at greater distances from anchor sites of the substrate being etched. At the masking level, the greater propensity for backside and lateral erosion of certain structures away from substrate anchor sites is exploited so that, at the completion of the etch process, suspended structures have acquired their respective desired widths.
Abstract:
A silicon-on-insulator (SOI) substrate including laminated layers of a substrate, an oxide layer, and a silicon layer in order. The oxide layer has an electrifying hole fluidly connected with the substrate and the electrifying hole is filled with a part of the silicon layer. A method for fabricating the floating structure is also disclosed which includes the steps of forming an oxide layer having a predetermined thickness on a substrate, forming one or more electrifying holes in an area of the oxide layer corresponding to an inner part of the floating structure, forming a silicon layer on the oxide layer including an electrification structure electrically connecting the silicon layer to the substrate, forming a pattern for the floating structure on the silicon layer, removing the oxide layer corresponding to an inner area of the pattern, forming a thermal oxide layer on a surface of the silicon layer, and removing the thermal oxide layer to form the floating structure.
Abstract:
A process for facilitating modification of an etched trench is provided. The process comprises: (a) providing a wafer comprising an etched trench, the trench having a photoresist plug at its base; and (b) removing a portion of the photoresist by subjecting the wafer to a biased oxygen plasma etch. The process is particularly suitable for preparing a trench for subsequent argon ion milling. Printhead integrated circuits fabricated by a process according to the invention have improved ink channel surface profiles and/or surface properties.
Abstract:
A method of making a microstructure with thin wall portions (T1-T3) includes a step of performing a first etching process to a material substrate having a laminate structure including a first conductive layer (11) and a second conductive layer (12) having a thickness of the thin wall portions (T1-T3), where the etching is performed from the side of the first conductive layer (11) thereby forming in the second conductive layer (12) pre thin wall portions (T1′-T3′) which has a pair of side surfaces apart from each other in an in-plane direction of the second conductive layer (12) and contact the first conductive layer (11). The method also includes a step of performing a second etching process from the side of the first conductive layer (11) for removing part of the first conductive layer (11) contacting the pre thin wall portions (T1′-T3′) to form the thin wall portions.
Abstract:
Methods of fabricating comb drive devices utilizing one or more sacrificial etch-buffers are disclosed. An illustrative fabrication method may include the steps of etching a pattern onto a wafer substrate defining one or more comb drive elements and sacrificial etch-buffers, liberating and removing one or more sacrificial etch-buffers prior to wafer bonding, bonding the etched wafer substrate to an underlying support substrate, and etching away the wafer substrate. In some embodiments, the sacrificial etch-buffers are removed after bonding the wafer to the support substrate. The sacrificial etch-buffers can be provided at one or more selective regions to provide greater uniformity in etch rate during etching. A comb drive device in accordance with an illustrative embodiment can include a number of interdigitated comb fingers each having a more uniform profile along their length and/or at their ends, producing less harmonic distortion during operation.