Method of in-situ depositing high dielectric constant Al2O3 and metal film on GaN base compound material

Abstract

This invention discloses a method for in-situ deposit high dielectric constant Al203 and a metallic film on a GaN compound material, which applies vacuum evaporation of electronic beams, takes over 4N pure Al203 particles and pure metallic film as the source to clean the chip and photoetch the evaporation window, then put the chip in a reaction chamber of an evaporation stand, evaporate the Al203film first under room temperature then the metallic film with the vacuum above 1.8x10-3Pa and bombard the chip with Ar ions, finally to set the density and coefficient of them, set the high voltage of the electronic beam at 10kv and the current is added with different values in terms of the needs, when the thickness of the film reaches to a demanded one, the current is reduced to zero quickly to take out the chip for strip off.

Description

technical field [0001] The invention belongs to the technical field of microelectronics, and relates to the process treatment in the manufacture of compound material devices, in particular to an in-situ deposition of high dielectric constant Al on a GaN base. 2 o 3 and a new approach to metal films Background technique [0002] With the requirement of high-speed communication and national defense modernization, the size of semiconductor devices is continuously reduced, and the thickness of the gate oxide layer must also be reduced accordingly. However, when the thickness of the gate oxide layer is less than 2nm, it will cause significant quantum tunneling effect, resulting in gate leakage current that seriously affects device performance. In the case of the same equivalent thickness of the gate dielectric, if a material with a high dielectric constant is used instead of SiO 2 As a gate dielectric, it can significantly reduce the gate leakage current caused by direct tunne...

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Problems solved by technology

[0029] 1) This method cannot form mass production;

[0030] 2) Generated Al 2 o 3 Film thickness cannot be precisely controlled;

[0031] 3) The thickness uniformity of each part in the sheet and the thickness repeatability between sheets are poor;

[0032] 4) Al produced by anodic oxidation 2 o 3 The biggest problem: its composition is not uniform in thickness

[0062] The above two processes require many steps, so the work efficiency is low and the production cost is high. In addition to an EB evaporation table, a DC reactive sputtering table of hundreds of thousands to more than 1 million yuan is required, and dozens of At the same time, due to the existence of harmful gases in the etching, it not only causes harmful pollution to the environment, but also, the film is exposed to the atmosphere 8 times during the processing process, which affects the electrical characteristics of the device, especially the stability of the device. And reliability and pass rate will have a great impact; in addition, use DC reactive sputtering equipment to deposit Al 2 o 3 A large amount of very expensive high-purity gas, such as high-purity Ar, is required, and Al is deposited 2 o 3 The uniformity and repeatability are not very good, the deposition rate and film thickness cannot be directly monitored, and the purpose of precise control cannot be achieved

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