A sacrificial substrate wafer is provided. A low resistivity etch stop layer is formed on or in the top surface of the wafer. The etch stop layer may be a highly doped, p+ type epitaxially grown layer, or an implanted p+ type boron layer, or an epitaxially grown p+ type SiGe layer. Various epitaxial layers, such as an n− type drift layer, and doped regions are then formed over the etch stop layer to form a vertical power device. The starting wafer is then removed by a combination of mechanical grinding/polishing to leave a thinner layer of the starting wafer. A chemical or plasma etch is then used to remove the remainder of the starting wafer, using the etch stop layer to automatically stop the etching. A bottom metal electrode is then formed on the etch stop layer. The etch stop layer injects hole carriers into the drift layer.

In one embodiment, a semiconductor manufacturing apparatus includes a container configured to contain a substrate, and a pipe configured to supply the container with liquid to treat the substrate. The apparatus further includes an ejector including a first passage where the liquid introduced from the pipe and the liquid introduced from the container are joined and pass through, and a first opening configured to eject the liquid that has passed through the first passage. Furthermore, the first passage has an area where a sectional area of the first passage becomes large as advancing downstream in the liquid.

After the various regions of a vertical power device are formed in or on the top surface of an n-type wafer, the wafer is thinned, such as by grinding. A drift layer may be n-type, and various n-type regions and p-type regions in the top surface contact a top metal electrode. A blanket dopant implant through the bottom surface of the thinned wafer is performed to form an n− buffer layer and a bottom p+ emitter layer. Energetic particles are injected through the bottom surface to intentionally damage the crystalline structure. A wet etch is performed, which etches the damaged crystal at a much greater rate, so some areas of the n− buffer layer are exposed. The bottom surface is metallized. The areas where the metal contacts the n− buffer layer form cathodes of an anti-parallel diode for conducting reverse voltages, such as voltage spikes from inductive loads.

A field effect transistor includes at least one line trench extending downward from a top surface of a channel region which laterally surrounds or underlies the at least one line trench, a gate dielectric contacting all surfaces of the at least one line trench and including a planar gate dielectric portion that extends over an entirety of a top surface of the channel region, a gate electrode, a source region, and a drain region.

A pixel circuit includes a trench etched into a front side surface of a semiconductor substrate. The trench includes a bottom surface etched along a <100> crystalline plane and a tilted side surface etched along a <111> crystalline plane that extends between the bottom surface and the front side surface. A floating diffusion is disposed in the semiconductor substrate beneath the bottom surface of the trench. A photodiode is disposed in the semiconductor substrate beneath the tilted side surface of the trench and is separated from the floating diffusion. The photodiode is configured to photogenerate image charge in response to incident light. A tilted transfer gate is disposed over at least a portion of the bottom surface and at least a portion of the tilted side surface of the trench. The tilted transfer gate is configured to transfer the image charge from the photodiode to the floating diffusion.

A method for forming a semiconductor device structure is provided. The method includes providing a chip structure including a substrate and a wiring structure over a first surface of the substrate. The method includes removing a first portion of the wiring structure adjacent to the hole to widen a second portion of the hole in the wiring structure. The second portion has a first width increasing in a first direction away from the substrate. The method includes forming a first seed layer over the wiring structure and in the hole. The method includes thinning the substrate from a second surface of the substrate until the first seed layer in the hole is exposed. The method includes forming a second seed layer over the second surface of the substrate and the first seed layer in the hole.

A method of fabricating a semiconductor device is described. A substrate is provided. A first semiconductor region of a first semiconductor material is formed over the substrate and adjacent a second semiconductor region of a second semiconductor material. The first and second semiconductor regions are crystalline. An etchant is selective to etch the first semiconductor region over the second semiconductor region. The entire first semiconductor region is implanted to form an amorphized semiconductor region. The amorphized semiconductor region is etched with the etchant using the second semiconductor region as a mask to remove the amorphized semiconductor region without removing the second semiconductor region.

A method for increasing oxygen content during TMAH etching includes using a wet etching machine, which has a liquid outlet of TMAH pipeline and a liquid outlet of TMAH return pipeline, both are connected to a mixed liquid tank, and a liquid inlet of TMAH return pipeline is connected to a return tank. The method includes: introducing nitrogen gas into the return tank containing TMAH, so as to reduce the oxygen content of TMAH in the return tank; introducing TMAH into the mixed liquid tank via the liquid outlet of the TMAH pipeline; introducing the TMAH in the return tank into the mixed liquid tank via the liquid outlet of the TMAH return pipeline. The method keeps the oxygen concentration in the mixed tank stable, so as to stabilize the TMAH etching rate, for a better sigma shaped silicon trench.

A semiconductor device includes a substrate; a first fin structure extending along a first lateral direction; a second fin structure extending along the first lateral direction; a first gate structure extending along a second lateral direction and straddles the first fin structure; a second gate structure extending along the second lateral direction and straddles the second fin structure. The semiconductor device further includes a dielectric cut structure that separates the first and second gate structures from each other. The dielectric cut structure extends into the substrate and comprises a first portion and a second portion. A width of the first portion along the second lateral direction increases with increasing depth into the substrate and a width of the second portion along the second lateral direction decreases with increasing depth into the substrate. The second portion is located below the first portion.

Provided is a method for growing a nanowire, including: providing a substrate with a base portion having a first surface and at least one support structure extending above or below the first surface; forming a dielectric coating on the at least one support structure; forming a photoresist coating over the substrate; forming a metal coating over at least a portion of the dielectric coating; removing a portion of the dielectric coating to expose a surface of the at least one support structure; removing a portion of the at least one support structure to form a nanowire growth surface; growing at least one nanowire on the nanowire growth surface of a corresponding one of the at least one support structure, wherein the nanowire comprises a root end attached to the growth surface and an opposing, free end extending from the root end; and elastically bending the at least one nanowire.