xenon difluoride gas phase etching barrier layer is prepared by the following steps: (1) spraying xenon difluoride gas onto the surface of the exposed barrier layer; (2) irradiating the barrier layer on the upper surface of the dielectric layer with a light beam, so that the etching rate of the barrier layer on the upper surface of the dielectric layer is higher than that of the barrier layer on the sidewalls of the trench and the connecting hole. This invention improves the etching rate of the barrier layer on the upper surface of the dielectric layer by irradiating it with a light beam, making the etching rate of the barrier layer on the upper surface of the dielectric layer higher than that of the barrier layer on the sidewalls of the trench and the connecting hole, thus avoiding over-etching of the barrier layer on the sidewalls of the trench and the connecting hole, improving the microscopic etching uniformity, and achieving better process results.
colorless crystal(s); readily prepared by mixing fluorine and xenon; enthalpy of sublimation 60.92 kJ/mol; monoclinic, a=0.5050 nm, b=0.5922nm, c=0.5771 nm [KIR78]
Xenon tetrafluoride is synthesised by heating a reaction mixture of xenon and fluorine gas within a sealed nickel vessel under high temperature and pressure at a molar ratio of approximately 1:5. The specific reaction steps are as follows: Xe + 2F₂ → XeF₄
fluorine gas at 20 atmospheres is conveyed into a pre-evacuated nickel or stainless steel reaction vessel. Xenon gas is then introduced to achieve a total pressure of 27–28 atmospheres. The xenon-fluorine mixture is maintained for at least 35 minutes to ensure thorough mixing. Subsequently, the mixture is ignited by a combustion initiator heated to 650–700°C via an electric current pulse. This induces a combustion reaction between the xenon and fluorine, yielding the target product.
