Vacuum shock protection method for process of feeding gas into ion source cavity

Abstract

The invention discloses a vacuum shock protection method for an ion implantation apparatus, which is used for a process of feeding a process gas into an ion source vacuum cavity. The method uses an ion source vacuum height gauge, a gas-feeding pipeline pressure sensor, a gas-feeding isolation valve, branch isolation valves and a mass flowmeter and belongs to the field of manufacturing of semiconductor devices. The method comprises the following steps: selecting an SDS low-pressure gas bottle specified by the process, setting the mass flowmeter to zero, opening the branch isolation valve corresponding to the gas bottle, opening the gas-feeding isolation valve for a while, closing the gas-feeding isolation valve for a while, monitoring the ion source vacuum height gauge in the opening and closing processes to avoid vacuum breaking of the ion source, repeating the opening and closing processes in such a manner until the detection value from the pressure sensor is less than the set value while opening the gas-feeding isolation valve, and setting the mass flowmeter to the initial value set in the process, and thus preventing residual gas in the gas-feeding pipeline and gas leaking out of the mass flowmeter from causing shock breakage on the ion source vacuum.

Description

technical field [0001] The invention relates to a method for preventing the impact of gas feeding in a vacuum chamber, in particular to a vacuum shock protection method for designing a vacuum chamber of an ion source when the process gas is fed in, and belongs to the field of semiconductor device manufacturing. Background technique [0002] When the ion implanter is working, process gas needs to be fed into the ion source cavity. Generally, there are more than 3 types of process gas. The incoming gas flow rate is controlled by the corresponding mass flow meter. Since the mass flow meter does not have the cut-off capability, the pressure of the branch circuit of the newly selected gas cylinder may reach 20 psi. When the ion source gas supply isolation valve is opened, there will be a great impact on the vacuum chamber. The impact may even damage the high vacuum of the ion source and affect the service life of the vacuum pump and ion source. A reliable method is needed to redu...

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Problems solved by technology

[0002] When the ion implanter is working, process gas needs to be fed into the ion source cavity. Generally, there are more than 3 types of process gas. The incoming gas flow rate is controlled by the corresponding mass flow meter. Since the mass flow meter does not have the cut-off capability, the pressure of the branch circuit of the newly selected gas cylinder may reach 20 psi. When the ion source gas supply isolation valve is opened, there will be a great impact on the vacuum chamber. The impact of the ion source may even damage the high vacuum of the ion source, which will affect the service life of the vacuum pump and the ion source. A reliable method is needed to reduce the impact damage to the vacuum

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