Aluminum etching technology of thin field aluminum gate and application thereof

Abstract

The invention relates to the etching technology, and discloses an aluminum etching technology of a thin field aluminum gate and an application thereof. The aluminum etching technology of the thin field aluminum gate comprises a main etching step and an over etching step. The technology is performed by using an applied material 8330 aluminum etching machine. The aluminum etching conditions of the thin field aluminum gate are listed as follows: in the main etching step, flow of chlorine is 30-40ml / min under the standard condition, flow of boron trichloride is 125-150ml / min under the standard condition, pressure is 35-45mTorr, negative bias voltage is from -220 to -180V, and a terminal point is automatically captured; and in the over etching step, flow of chlorine is 30-40ml / min under the standard condition, flow of boron trichloride is 125-150ml / min under the standard condition, pressure is 35-45mTorr, negative bias voltage is from -220 to -180V, and duration of over etching is 1min. With application of the technical scheme, selection ratio of an aluminum ratio oxide layer can be substantially enhanced, gate oxide loss can be reduced and thus product yield rate can be enhanced.

Description

technical field [0001] The invention relates to an etching process, in particular to an aluminum etching process of a thin-field aluminum grid and its application. Background technique [0002] Aluminum etching is one of the main etching processes in the field of semiconductor manufacturing. Its main function is to transfer the designed metal gate and wiring pattern to the product, so as to realize the function of gate or wiring. The aluminum etching machines in 6-inch semiconductor manufacturing plants are generally Applied Materials 8330 aluminum etching machines and LAM9600 aluminum etching machines. [0003] In the field of semiconductor manufacturing, the maximum selection ratio Al / OX (aluminum to oxide layer) that Applied Materials 8330 aluminum etching machine can do by conventional methods is 3 / 1, because of the characteristics of the hardware structure of Applied Materials 8330 aluminum etching machine equipment itself As a result, its anisotropic ability is very w...

AI Technical Summary

Problems solved by technology

The gate oxide of the thin field aluminum gate product is very thin, only 520 Angstroms Left and right, the low selection ratio makes it extremely difficult for the Applied Materials 8330 aluminum etcher to etch aluminum on thin-field aluminum grids

[0005] 2.5 micron thin field aluminum gate process, the gate oxide under the aluminum is only and remain after dry etching The above gate oxide, that is, the maximum gate oxide loss point can only be In the prior art, when the Applied Materials 8330 aluminum etching machine adopts the standard CMOS (Complementary Metal Oxide Semiconductor, Complementary Metal Oxide Semiconductor) process to etch aluminum, it uses a mixed gas of chlorine, boron trichloride and trifluoromethane to etch Etching metal aluminum, when etching the aluminum layer of the thin field aluminum gate, there is a technical problem that the selectivity ratio of aluminum to the oxide layer is too low. aluminum, the gate oxide loss is generally in the Far greater than the maximum loss allowed by the gate oxide

[0006] The defect of the existing technology is that when the thin-field aluminum gate is operated by the standard CMOS process on the Applied Materials 8330 aluminum etching machine, the selection of aluminum to the oxide layer is relatively low, resulting in the gate oxide being easily etched through and damaging the substrate, resulting in product scrapped

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