Abstract: A method of etching a semiconductor substrate. The method includes the steps of applying a photoresist etch mask layer to a device surface of the substrate. A select first area of the photoresist etch mask is masked, imaged and developed. A select second area of the photoresist etch mask layer is irradiated to assist in post etch stripping of the etch mask layer from the select second area. The substrate is etched to form fluid supply slots through a thickness of the substrate. At least the select second area of the etch mask layer is removed from the substrate, whereby mask layer residue formed from the select second area of the etch mask layer is significantly reduced.

Abstract: A method of micro-machining a semiconductor substrate to form one or more through slots therein. The semiconductor substrate has a device side and a fluid side opposite the device side. The method includes diffusing a p-type doping material into the device side of the semiconductor substrate in one or more through slot locations to be etched through a thickness of the substrates. The semiconductor substrate is then etched with a dry etch process from the device side of the substrate to the fluid side of the substrate so that one or more through slots having a reentrant profile are formed in the substrate.

Abstract: A micro-fluid ejection assembly and method therefor. The micro-fluid ejection assembly includes a silicon substrate having a fluid supply slot therein. The fluid supply slot is formed by an etch process conducted on a substrate using, a first etch mask circumscribing the fluid supply slot, and a second etch mask applied over a functional layer on the substrate.

Abstract: Methods of forming a fluid channel in a semiconductor substrate may include providing a semiconductor substrate having a backside and a device side, wherein the device side is configured to secure ink ejecting devices thereon and applying a material layer to the backside of the semiconductor substrate. The method may further include providing a gray scale mask configured with a pattern corresponding to a fluid channel having a plurality of slots, exposing the material layer to sufficient light radiation energy through the gray scale mask and etching the exposed material layer and the semiconductor substrate through to the device side of the semiconductor substrate.

Abstract: A method of substantially simultaneously forming at least two fluid supply slots through a thickness of semiconductor substrate from a first surface to a second surface thereof. The method includes the steps of applying a photoresist layer to the first surface of the semiconductor substrate. The photoresist layer is patterned and developed using a gray scale mask for a first fluid supply slot. The semiconductor substrate is then reactive ion etched, to form the at least two fluid supply slots through the thickness of the substrate. The first fluid supply slot is substantially wider than the second fluid supply slot, and the first and second fluid supply slots are etched through the substrate at substantially the same rate.

Abstract: Methods of forming a fluid channel in a semiconductor substrate may include applying a material layer to at least one surface of the semiconductor substrate. The method may further include manipulating the material layer to form a surface topography corresponding to a channel, the surface topography being configured to control directionality of ion bombardment of said substrate along electromagnetic field lines in a plasma sheath coupled to said surface topography.

Abstract: A method for improving fluidic flow for a microfluidic device having a through hole or slot therein. The method includes the steps of forming one or more openings through at least part of a thickness of a substrate from a first surface to an opposite second surface using a reactive ion etching process whereby an etch stop layer is applied to side wall surfaces in the one or more openings during alternating etching and passivating steps as the openings are etched through at least a portion of the substrate. Substantially all of the etch stop layer coating is removed from the side wall surfaces by treating the side wall surfaces using a method selected from chemical treatment and mechanical treatment, whereby a surface energy of the treated side wall surfaces is increased relative to a surface energy of the side wall surfaces containing the etch stop layer coating.

Abstract: Methods of micro-machining a semiconductor substrate to form through fluid feed slots therein. One method includes providing a semiconductor substrate wafer having a thickness greater than about 500 microns and having a device side and a back side opposite the device side. The back side of the wafer is mechanically ground to provide a wafer having a thickness ranging from about 100 up to about 500 microns. Dry etching is conducted on the wafer from a device side thereof to form a plurality of reentrant fluid feed slots in the wafer from the device side to the back side of the wafer.

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: A method of etching a semiconductor substrate. The method includes the steps of applying a photoresist etch mask layer to a device surface of the substrate. A select first area of the photoresist etch mask is masked, imaged and developed. A select second area of the photoresist etch mask layer is irradiated to assist in post etch stripping of the etch mask layer from the select second area. The substrate is etched to form fluid supply slots through a thickness of the substrate. At least the select second area of the etch mask layer is removed from the substrate, whereby mask layer residue formed from the select second area of the etch mask layer is significantly reduced.

Abstract: A method of micro-machining a semiconductor substrate to form one or more through slots therein. The semiconductor substrate has a device side and a fluid side opposite the device side. The method includes diffusing a p-type doping material into the device side of the semiconductor substrate in one or more through slot locations to be etched through a thickness of the substrate. The semiconductor substrate is then etched with a dry etch process from the device side of the substrate to the fluid side of the substrate so that one or more through slots having a reentrant profile are formed in the substrate.

Abstract: A method of micro-machining a semiconductor substrate to form through slots therein and substrates made by the method. The method includes providing a dry etching chamber having a platen for holding a semiconductor substrate. During an etching cycle of a dry etch process for the semiconductor substrate, a source power is decreased, a chamber pressure is decreased from a first pressure to a second pressure, and a platen power is increased from a first power to a second power. Through slots in the substrate provided by the method can have a reentrant profile for fluid flow therethrough.

Abstract: A method for improving fluidic flow for a microfluidic device having a through hole or slot therein. The method includes the steps of forming one or more openings through at least part of a thickness of a substrate from a first surface to an opposite second surface using a reactive ion etching process whereby an etch stop layer is applied to side wall surfaces in the one or more openings during alternating etching and passivating steps as the openings are etched through at least a portion of the substrate. Substantially all of the etch stop layer coating is removed from the side wall surfaces by treating the side wall surfaces using a method selected from chemical treatment and mechanical treatment, whereby a surface energy of the treated side wall surfaces is increased relative to a surface energy of the side wall surfaces containing the etch stop layer coating.