Etching solution composition for titanium-aluminum-titanium metal laminated membrane

Abstract

The invention relates to an etching solution composition for a titanium-aluminum-titanium metal laminated membrane consisting of a titanium metal membrane, an aluminum metal membrane and a titanium metal membrane. The composition consists of fluorides, oxidizing acid, non-oxidizing alkali metal salt and water, wherein the non-oxidizing alkali metal salt is preferentially at least one of water-soluble lithium, potassium and sodium salts; the mass percent concentration of the fluorides, the oxidizing acid and the non-oxidizing alkali metal salt are 0.01-5 percent, 0.1-30 percent and 0.0004-0.35 percent, respectively. Compared with the prior art, the etching solution composition has the advantages that the three laminated metal membranes can be etched together, the lateral erosion amount can be effectively reduced, the etching uniformity is improved, and the obtained taper angle is 25 degrees below. In addition, the etching solution composition adopts low-price non-oxidizing salts or mixtures thereof instead of high-price salt-type auxiliary oxidants, so that the production cost is reduced, and the balance between the cost and performance is achieved.

Description

technical field [0001] The invention relates to an etchant suitable for wet etching metal layers in the manufacture of semiconductor devices, in particular to an etchant composition for a titanium-aluminum-titanium metal laminated film composed of a titanium metal film, an aluminum metal film and a titanium metal film. Background technique [0002] Because aluminum or aluminum alloy is cheap and has very low resistance, it is often used in materials such as gates, sources and drains of liquid crystal displays. However, due to the poor adhesion between aluminum or aluminum alloy and the glass substrate as the base film, it is easily corroded by chemical liquid and heat, so titanium or titanium alloy is used to form a laminated film on the lower part of aluminum or aluminum alloy for electrode materials . At present, the industry has developed a new type of three-layer metal laminated film, which includes an upper layer made of titanium or a titanium base layer mainly made of...

AI Technical Summary

Problems solved by technology

For this titanium-aluminum-titanium three-layer metal laminated film, a kind of etchant composition of fluoride+nitric acid or methanesulfonic acid oxidant that does not contain hydrofluoric acid has also been developed (such as the Chinese patent application number 200610009536.5, Japanese Patent Application Publication No. 2007-67367), the oxidizing agent may also contain a certain oxidizing salt as an auxiliary oxidizing agent other than nitric acid or methanesulfonic acid, and the cation in the oxidizing salt is only used as a counter ion of the auxiliary oxidizing agent. This patent does not include The role of cations is not mentioned, and the auxiliary oxidizing agents used are limited to oxidizing salts or oxidizing acids, and the cost is high

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