Embodiments relate to a semiconductor structure and a fabrication method. The method includes: providing a substrate, where a first trench is formed in the substrate; forming a first dielectric layer and a protective material layer in the first trench, where the first dielectric layer is positioned between the protective material layer and the substrate, and an upper surface of the first dielectric layer is lower than an upper surface of the substrate, to expose a portion of a side wall of the first trench; forming a second dielectric layer on the exposed side wall of the first trench; and filling the second trench to form a work function structure, where the work function structure includes a first work function layer and a second work function layer, where the second work function layer is positioned on an upper surface of the first work function layer.

Methods and apparatuses for precise trimming of silicon-containing materials are provided. Methods involve oxidizing silicon-containing materials and thermally removing the oxidized silicon-containing materials at particular temperatures for a self-limiting etch process. Methods also involve a surface reaction limited process using a halogen source and modulated temperature and exposure duration to etch small amounts of silicon-containing materials. Apparatuses are capable of flowing multiple oxidizers at particular temperature ranges to precisely etch substrates.

A semiconductor substrate includes a silicon carbide substrate, a first nitride film in contact with the upper surface of the silicon carbide substrate, a second nitride film in contact with an upper surface of the first nitride film, and a silicon oxide film in contact with the upper surface of the second nitride film. The first nitride layer is more nitrogen-rich than the second nitride layer.

According to one aspect of the technique of the present disclosure, there is provided a method of manufacturing a semiconductor device including: (a) providing a semiconductor processing apparatus including a substrate process chamber, a coil and a substrate support; (b) placing a target substrate with a concave structure of a silicon film on a substrate support, wherein a deteriorated layer is formed on an inner surface of the concave structure by deterioration of a surface layer of the silicon film due to an etching process; (c) supplying an oxygen-containing gas into the substrate process chamber; (d) applying a high frequency power to the coil to generate plasma of the oxygen-containing gas; and (e) oxidizing, by the plasma, a surface of the silicon film exposed in the concave structure wherein the deteriorated layer is formed on the surface.

Semiconductor device structures having a liner layer in an interlayer dielectric structure are provided. In one example, a semiconductor device includes an active area on a substrate, the active area comprising a source/drain region, a gate structure over the active area, the source/drain region being proximate the gate structure, a spacer feature along a sidewall of the gate structure, a contact etching stop layer on the spacer feature, a liner oxide layer on the contact etching stop layer, and an interlayer dielectric layer on the liner oxide layer, wherein the liner oxide layer has an oxygen concentration level greater than the interlayer dielectric layer.

A semiconductor device includes a gate structure on a substrate, a first spacer on sidewalls of gate structure, a second spacer on sidewalls of the first spacer, a polymer block adjacent to the first spacer and on a corner between the gate structure and the substrate, an interfacial layer under the polymer block, and a source/drain region adjacent to two sides of the first spacer. Preferably, the polymer block is surrounded by the first spacer, the interfacial layer, and the second spacer.

A method of processing a substrate includes forming a channel through a substrate, depositing a layer of polycrystalline silicon on sidewalls of the channel, and oxidizing uncovered surfaces of the polycrystalline silicon with an oxidation agent. The oxidizing agent causes formation of an oxidized layer, the oxidized layer having a uniform thickness on uncovered surfaces of the polycrystalline silicon. The method includes removing the oxidized layer from the channel with a removal agent, and repeating steps of oxidizing uncovered surfaces and removing the oxidized layer until removing a predetermined amount of the layer of polycrystalline silicon.

A semiconductor device having a gate structure and a method of forming same are provided. The semiconductor device includes a substrate and a gate structure over the substrate. The substrate has a first region and a second region. The gate structure extends across an interface between the first region and the second region. The gate structure includes a first gate dielectric layer over the first region, a second gate dielectric layer over the second region, a first work function layer over the first gate dielectric layer, a barrier layer along a sidewall of the first work function layer and above the interface between the first region and the second region, and a second work function layer over the first work function layer, the barrier layer and the second gate dielectric layer. The second work function layer is in physical contact with a top surface of the first work function layer.

Method for selectively oxidizing the dielectric surface of a substrate surface comprising a dielectric surface and a metal surface are discussed. Method for cleaning a substrate surface comprising a dielectric surface and a metal surface are also discussed. The disclosed methods oxidize the dielectric surface and/or clean the substrate surface using a plasma generated from hydrogen gas and oxygen gas. The disclosed method may be performed in a single step without the use of separate competing oxidation and reduction reactions. The disclosed methods may be performed at a constant temperature and/or within a single processing chamber.

The present application provides a method for improving continuity of a work function thin film, forming a tunneling oxide layer on a substrate; forming an isolation layer on the tunneling oxide layer; forming a work function thin film on the isolation layer, the work function thin film serves as a floating gate in a semi-floating gate device to store charges and conduction electrons, performing a heat treatment on the tunneling oxide layer, the isolation layer and the work function layer, the isolation layer reacts with a surface of the tunneling oxide layer to form a dense barrier layer, the isolation layer reacts with O in the tunneling oxide layer to form a new tunneling oxide layer, the heat treatment lasts until the isolation layer is fully consumed, and the work function thin film remaining after the reaction uniformly covers an upper surface of the dense barrier layer.