3099 results about "Carbon nitride" patented technology

Methods of selectively etching tungsten relative to silicon-containing films (e.g. silicon oxide, silicon carbon nitride and (poly)silicon) as well as tungsten oxide are described. The methods include a remote plasma etch formed from a fluorine-containing precursor and / or hydrogen (H2). Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the tungsten. The plasma effluents react with exposed surfaces and selectively remove tungsten while very slowly removing other exposed materials. Sequential and simultaneous methods are included to remove thin tungsten oxide which may, for example, result from exposure to the atmosphere.

Methods are described herein for selectively etching titanium nitride relative to dielectric films, which may include, for example, alternative metals and metal oxides lacking in titanium and / or silicon-containing films (e.g. silicon oxide, silicon carbon nitride and low-K dielectric films). The methods include a remote plasma etch formed from a chlorine-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the titanium nitride. The plasma effluents react with exposed surfaces and selectively remove titanium nitride while very slowly removing the other exposed materials. The substrate processing region may also contain a plasma to facilitate breaking through any titanium oxide layer present on the titanium nitride. The plasma in the substrate processing region may be gently biased relative to the substrate to enhance removal rate of the titanium oxide layer.

A method of etching patterned heterogeneous silicon-containing structures is described and includes a remote plasma etch with inverted selectivity compared to existing remote plasma etches. The methods may be used to conformally trim polysilicon while removing little or no silicon oxide. More generally, silicon-containing films containing less oxygen are removed more rapidly than silicon-containing films which contain more oxygen. Other exemplary applications include trimming silicon carbon nitride films while essentially retaining silicon oxycarbide. Applications such as these are enabled by the methods presented herein and enable new process flows. These process flows are expected to become desirable for a variety of finer linewidth structures. Methods contained herein may also be used to etch silicon-containing films faster than nitrogen-and-silicon containing films having a greater concentration of nitrogen.

A method of etching exposed silicon-nitrogen-and-carbon-containing material on patterned heterogeneous structures is described and includes a remote plasma etch formed from a fluorine-containing precursor and an oxygen-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the exposed regions of silicon-nitrogen-and-carbon-containing material. The plasma effluents react with the patterned heterogeneous structures to selectively remove silicon-nitrogen-and-carbon-containing material from the exposed silicon-nitrogen-and-carbon-containing material regions while very slowly removing selected other exposed materials. The silicon-nitrogen-and-carbon-containing material selectivity results partly from the presence of an ion suppression element positioned between the remote plasma and the substrate processing region. The ion suppression element controls the number of ionically-charged species that reach the substrate. The methods may be used to selectively remove silicon-nitrogen-and-carbon-containing material at a faster rate than exposed silicon oxide or exposed silicon nitride.

The invention relates to a method for preparing a graphite-phase carbon nitride (g-C3N4) material. The method includes the steps that a carbon nitride precursor and ammonium salt are evenly mixed, and then calcination is conducted so that the porous g-C3N4 material can be obtained. The ammonium salt is any one of ammonium base salts capable of generating ammonia gas through thermal decomposition or is the combination of at least two of the ammonium base salts. In the preparation process of the g-C3N4 material, the ammonium salt is added into the carbon nitride precursor to be mixed. In the high-temperature calcining process, the ammonium salt is subjected to pyrogenic decomposition to generate gas, a pore-forming effect on the g-C3N4 material is achieved, and the cellular porous g-C3N4 material is obtained. In the preparation process of the g-C3N4 material, template agents are not used, and thus the method is simple, efficient and environmentally friendly; the prepared g-C3N4 material is high in photocatalytic activity and can be used in the pollution control processes such as exhaust gas and wastewater treatment.

Boron nitride nanotubes are prepared by a process which includes:(a) creating a source of boron vapor;(b) mixing the boron vapor with nitrogen gas so that a mixture of boron vapor and nitrogen gas is present at a nucleation site, which is a surface, the nitrogen gas being provided at a pressure elevated above atmospheric, e.g., from greater than about 2 atmospheres up to about 250 atmospheres; and(c) harvesting boron nitride nanotubes, which are formed at the nucleation site.