Quartz bell jar used for microwave plasma chemical vapor deposition device

Abstract

The invention discloses a quartz bell jar used for a microwave plasma chemical vapor deposition device. The lower end of quartz bell jar is provided with a cylindrical barrel; the upper end of the quartz bell jar is provided with a semispherical seal with a plurality of quartz circular rings; the quartz circular rings are distributed, in the form of a horizontal array, on the middle lower portion of the semispherical seal; the outer diameters of the quartz circular rings are the same as the outer diameter of the cylindrical barrel; and in case of externally applying air-cooling, the quartz circular rings achieve the effect of increasing heat dissipation. The quartz bell jar is applied to a microwave plasma chemical vapor deposition process, so that the heat dissipation capacity of the quartz bell jar can be effectively improved, the temperature of the quartz bell jar can be reduced, the deposition, to the inner surface of the semispherical seal, of active groups is decelerated, influences of sediments to plasma discharge and sample pollution are reduced, and etching, to the quartz bell jar, of the plasmas is relieved while the temperature of the quartz bell jar is reduced; and the quartz bell jar can be adopted to properly improve input microwave power, to increase the deposition rate of samples, and to improve the quality of the samples.

Description

Technical field [0001] The invention relates to the technical field of microwave plasma chemical vapor deposition, in particular to a quartz bell jar used in a microwave plasma chemical vapor deposition device. technical background [0002] At present, the quartz bell-jar type microwave plasma chemical vapor deposition apparatus under medium power operation is still widely used. The advantages of this type of device are that the quartz bell chamber is easy to clean and the quartz bell is easy to replace. However, in order to improve the deposition rate and quality, it is necessary to increase the power of the microwave input. Sometimes in order to obtain a thicker sample, it is necessary to extend the single processing time, which will increase the temperature of the quartz bell, especially the hemispherical seal at the upper end of the quartz bell , The active groups in the chamber are easy to deposit on the inner surface of the hemispherical quartz seal, which will interfere wi...

AI Technical Summary

Problems solved by technology

However, in order to improve the deposition rate and quality, it is necessary to appropriately increase the input power of the microwave. Sometimes in order to obtain a thicker sample, it is necessary to extend the single processing time, which will cause the temperature of the quartz bell jar to rise, especially the hemispherical seal at the upper end of the quartz bell jar. , the active groups in the chamber are easy to deposit on the inner surface of the hemispherical quartz seal, which will interfere with the microwave penetration of the quartz bell jar and affect the plasma discharge, and the shedding of the deposits during the process will contaminate the sample, and if the heat dissipation capacity of the quartz bell jar If the temperature is poor, it will also affect the temperature of the sample. Sometimes lowering the temperature of the quartz bell jar will also reduce the etching of the quartz bell jar by the plasma and reduce the silicon pollution caused by the sample.

[0003] For example, when microwave plasma chemical vapor deposition of diamond film or diamond single crystal is carried out, it is easy to form carbon inside the quartz bell jar. After the quartz bell jar is carbonized, even if it is cleaned effectively, it may also form carbon in situ during the next growth. ; If the quartz bell is etched, the damage to the quartz bell will be irreversible

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