Provided is a back grinding adhesive sheet which can adequately protect protrusions provided to a semiconductor wafer, and with which back grinding can be adequately performed. The present invention provides a back grinding adhesive sheet for a semiconductor wafer having protrusions, the back grinding adhesive sheet comprising a non-adhesive cushion layer, and an adhesive layer provided on the cushion layer. The adhesive layer has an opening with a smaller diameter than the diameter of the semiconductor wafer, and the outer edge of the semiconductor wafer is adhered to the adhesive layer such that the protrusions on the semiconductor wafer are positioned inside the opening. The protrusions are protected by the cushion layer when the semiconductor wafer is in the state of being adhered to the adhesive layer. The adhesive sheet satisfies at least one of the following conditions (1)-(2). (1) When the cushion layer is cut out using the dumbbell from JISZ1702 and is stretched 25% at a gauge length of 40 mm and a tensile speed of 300 mm/min, the tensile stress is 2-30N/10 mm. (2) The cushion layer is formed from a thermoplastic resin that has a melt flow rate (JISK7210, 125° C./10.0 kg load) of 0.2-30 g/10 min, and a melting point of 60-110° C.

A method that forms a sacrificial fill material that can be selectively removed for forming a backside contact via for a transistor backside power rail. In some embodiments, the method may include performing an etching process on a substrate with an opening that is conformally coated with an oxide layer, wherein the etching process is an anisotropic dry etch process using a chlorine gas to remove the oxide layer from a field of the substrate and only from a bottom portion of the opening, and wherein the etching process forms a partial oxide spacer in the opening and increases a depth of the opening and epitaxially growing the sacrificial fill material in the opening by flowing a hydrogen chloride gas at a rate of approximately 60 sccm to approximately 90 sccm in a chamber pressure of approximately 1 Torr to approximately 100 Torr.

The present invention relates to a cleaning fluid containing components (A) to (C) and 0.001 mass % or less of a surfactant, in which component (A) is a compound represented by formula (1); component (B) is an alkaline compound; and component (C) is water,

##STR00001## in formula (1), R.sub.1 and R.sub.2 independently represent a hydroxyl group or a phenol group.

A method of processing a semiconductor wafer is provided. The method includes providing a semiconductor wafer having a front side and a back side, the semiconductor wafer provided with a circuit layer at the front side and a patterned surface at the back side, forming a sacrificial layer on the back side, mounting a tape on the sacrificial layer, the sacrificial layer isolating the patterned surface from the tape, wherein adhesion strength between the sacrificial layer and the patterned surface is larger than that between the sacrificial layer and the tape, dicing the semiconductor wafer at the back side through the tape, defining individual chips on the semiconductor wafer, and expanding the tape to separate the chips from each other.

The invention relates to a method of processing a semiconductor in the semiconductor wafer is disposed on a susceptor in a coating apparatus and processed, wherein an etching gas is passed through the coating apparatus in an etching step. The invention further relates to a control system for controlling a coating apparatus for processing a semiconductor water, to a plant for processing a semiconductor wafer having a coating apparatus which comprises the control system, and a semiconductor wafer. A first side of the semiconductor wafer which has been subjected to a polishing operation by CMP, or a second side of the semiconductor wafer opposite the first side, is coated with a protective layer before processing.

A wafer thinning method and a wafer structure are provided. In the wafer thinning method, a to-be-thinned wafer is provided, and the to-be-thinned wafer is grinded on a rear surface of the to-be-thinned wafer. Then, a first planarization process is performed on a rear surface of the grinded wafer to restore surface flatness of the grinded wafer, and a second planarization process is performed on a rear surface of the wafer obtained after the first planarization process is performed until a target thinned thickness is reached.

A method for processing a wide band gap semiconductor wafer includes: depositing a support layer including semiconductor material at a back side of a wide band gap semiconductor wafer, the wide band gap semiconductor wafer having a band gap larger than the band gap of silicon; depositing an epitaxial layer at a front side of the wide band gap semiconductor wafer; and splitting the wide band gap semiconductor wafer along a splitting region to obtain a device wafer comprising at least a part of the epitaxial layer, and a remaining wafer comprising the support layer.

Provided is a method of double-side polishing a silicon wafer using a double-side polishing apparatus, the method including in succession: a first polishing step of performing double-side polishing while supplying a first polishing agent that is an alkaline aqueous solution containing abrasive grains to the polishing cloths; a polishing agent switching step of stopping the supply of the first polishing agent and starting the supply of a second polishing agent that is an alkaline aqueous solution containing a water-soluble polymer with no abrasive grains, with the polishing cloths of the upper plate and the lower plate being in contact with the front surface and the back surface of the silicon wafer, respectively and with the upper plate and the lower plate being continuously rotated; and a second polishing step of performing double-side polishing while supplying the second polishing agent to the polishing cloths.

A method includes providing a semiconductor substrate having a first side and a second side opposite to the first side, forming at least one radio frequency device at the first side; thinning the semiconductor substrate from the second side; and processing the second side of the thinned semiconductor substrate to reduce leakage currents or to improve a radio frequency linearity of the at least one radio frequency device.

A method for creating at least one cavity in a semiconductor substrate including the steps of: (a) partially ablating the semiconductor substrate from the top side with a laser to form a trench in the semiconductor substrate surrounding a cross section of the semiconductor material having the desired shape, (b) machining the backside of the semiconductor substrate partially ablated in step (a) to reduce the semiconductor substrate to a final thickness that is equal to or less than the laser ablation depth to form a plug of semiconductor material unattached to a remainder of the semiconductor substrate; and (c) removing the plug of semiconductor material from the semiconductor substrate to form the at least one cavity with cross section of desired shape extending through the semiconductor substrate.