Gas treatment apparatus

Abstract

The present invention relates to gas treatment plants. The film-forming device (100) includes: a chamber (1) for accommodating wafers; a mounting table arranged in the chamber (1) for mounting the wafers; a mounting table arranged at a position opposite to the mounting table, facing into the chamber (1) A spray head (4) for spraying processing gas; and an exhaust mechanism for exhausting the inside of the chamber (1). The shower head (4) includes: a central portion (46) formed with a large number of gas ejection holes (45a, 45b) for ejecting processing gases; a gas ejection hole (45a) that is located on the outer peripheral side of the central portion (46) , 45b), the film forming device (100) further includes a heat dissipation mechanism for dissipating heat from the spray head (4) from the entire circumference of the outer periphery (47) to the atmosphere side.

Description

technical field [0001] The present invention relates to a gas processing apparatus for gas processing a substrate to be processed using a processing gas. Background technique [0002] In recent years, based on the requirements of high integration and high speed of LSI, the design rules of semiconductor elements constituting LSI have become increasingly finer. At the same time, in CMOS devices, SiO 2 EOT (Equivalent Oxide Thickness: Equivalent Oxide Thickness) of film thickness in terms of capacitance is a value of about 1.5 nm or less. As a material for realizing such a thin insulating film without increasing gate leakage current, a high dielectric constant material, that is, a so-called High-k material, is attracting attention. [0003] In the case of using a high dielectric constant material as the gate insulating film, it must be thermodynamically stable without interdiffusion with the silicon substrate. From this point of view, oxides of hafnium, zirconium, or lanthanum...

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Problems solved by technology

[0007] However, as described above, when a flat gas diffusion space is provided in the shower head, since this space prevents transfer (radiation) to the back side, it is heated by radiant heat from the mounting table for heating the semiconductor wafer. The film causes the temperature rise of the nozzle

[0008] Especially in MOCVD, since the thermal decomposition of the raw material gas is used, when the temperature of the shower head rises and the temperature exceeds the thermal decomposition temperature of the raw material gas, an undesirable thermal decomposition reaction occurs inside the shower head, in the piping in front of the shower head, etc., The concentration of the raw material gas supplied to the semiconductor wafer is lowered, or the reflectance of the shower head is lowered due to the decomposition product of the raw material gas attached to the surface of the shower head, and the temperature of the semiconductor wafer is lowered, resulting in a poor film formation.

[0009] Moreover, when the temperature of the shower head rises over time as described above, it becomes the cause of large variations in film quality and film composition, and the above-mentioned decomposition products are peeled off from the surface of the shower head to fly and fall on the semiconductor wafer as foreign matter, which also causes Causes of poor film formation

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