Copper target material as well as preparation method and application thereof

Abstract

The invention provides a copper target material as well as a preparation method and application thereof. The grain size in the copper target material is smaller than or equal to 10 [mu] m, and the proportion of grains with the grain orientation being {110} in the copper target material is 50% -70%. The copper target material is applied to sputtering film forming of an integrated circuit, it can be guaranteed that the performance of the copper target material is stable in the sputtering process, a uniform thin film is formed on the integrated circuit, and the requirement for the sputtering performance below a 7 nm process node is met. The preparation method of the copper target material comprises the step of sequentially carrying out hot forging, first heat treatment, cold forging, second heat treatment, first static pressing, second static pressing and rolling on a copper cast ingot. The preparation method is simple and high in work efficiency.

Description

technical field [0001] The invention relates to the technical field of target materials, in particular to a copper target material and its preparation method and application. Background technique [0002] Ultra High Purity Copper (UHPC for short) refers to copper with a purity ≥ 6N, and its impurity content ≤ 1ppm, so it has the smallest grain boundary area and few internal lattice defects. As a result, ultra-high-purity copper has excellent electromigration resistance, electrical conductivity, ductility, thermal conductivity, and corrosion resistance. In addition, its recrystallization temperature is also low. At present, ultra-high-purity copper has been widely used in the interconnection materials of ultra-large integrated circuits below the 45nm technology node. [0003] With the rapid development of ultra-large-scale integrated circuits, the size of semiconductor chips has been reduced to the nanometer level, and the RC delay and electromigration of metal interconnect...

AI Technical Summary

Problems solved by technology

[0005] CN112063976A discloses an ultra-high-purity copper target and its grain control method. The method includes hot forging the ultra-high-purity copper parts, and performing crystallization heat treatment after cooling; cold forging the processed copper parts treatment, then crystallization heat treatment again, and then rolling to obtain ultra-high-purity copper targets, but this method does not clarify the proportion of grain orientation

[0006] CN104128740A discloses a method for preparing a copper target. The preparation method includes: first densifying a copper blank by using a hot forging process, and forming a first copper target blank after cooling; rolling the first The copper target blank is reduced in thickness by 10-50% to form a second copper target blank; the second copper target blank is annealed to form a copper target, but this method does not clarify the Grain size and grain orientation ratio

[0007] CN104746020B discloses a copper alloy target processing method, the method mainly includes: heating the high-purity copper alloy ingot evenly and keeping it warm in a heating furnace, using forging equipment to carry out hot forging on the ingot along X / Y / Z directions respectively The forged blank is subjected to multi-pass reciprocating cold rolling on a two-roll rolling mill, and the rolled blank is subjected to heat treatment and heat preservation to obtain a high-purity copper alloy sputtering target blank. However, in the method, the average grain size is below 30 μm, and the weaving The texture orientation is randomly distributed, which does not meet the sputtering performance requirements below the 7nm process node of the integrated circuit

Images