A germanium arsenic selenium tellurium alloy target material and preparation method thereof

Abstract

The invention discloses a low-oxygen large-size germanium-arsenic-selenium-tellurium alloy target and a preparation method thereof. The alloy includes the following components and their atomic percentages: 15-25% germanium; 20-40% arsenic; 30-40% selenium 50%; tellurium 3 to 10%, the sum of the atomic percentages of the above raw materials after mixing is 100%; the preparation method includes distilling and purifying the raw materials of the target material and mixing them into a quartz tube according to the above ratio, and then vacuum fusing and sealing Add 10ppm of high-purity GeCl 4 , melted again. The quartz tube after secondary fusing is put into a swing furnace for melting and annealing to obtain a small-sized ingot, and the small-sized ingot is diffused and connected by hot isostatic pressing to prepare a large-sized alloy target billet, which is machined into a Large size germanium arsenic selenium tellurium alloy target. The specification of the alloy target prepared by this method is Dia (150-450mm)×Th (5-30mm), the impurity oxygen content is less than 100ppm, and the relative density is greater than 99%.

Description

technical field [0001] The invention belongs to the technical field of semiconductor memory, and relates to a preparation method of a phase-change storage and threshold switch material, in particular to a preparation method of a low-oxygen large-size germanium-arsenic-selenium-tellurium phase-change alloy target. Background technique [0002] Phase change memory (PCM for short) is a kind of memory that uses the change of material phase to realize information storage. The principle is to use electric pulse (heat) to make the storage medium material convert between crystalline state (low resistance) and amorphous state (high resistance) to realize the writing and erasing of information, and the reading of information depends on the change of measuring resistance to fulfill. Phase change memory has the advantages of non-volatility, high storage density, long cycle life, small component size, low power consumption, and compatibility with existing integrated circuit technology. ...

AI Technical Summary

Problems solved by technology

The direct melting method, such as a high-purity chalcogenide phase-change alloy target and its preparation method invented by Ningbo University (authorized announcement number CN 102637822B), uses dense tube synthesis to directly melt the alloy target, but is limited by quartz tubes, Due to the size of the melting furnace and the requirements of the melting process, this method cannot be used to prepare large-sized targets (such as Φ>150mm)

The powder sintering method is currently the mainstream method for preparing large-sized targets. The main process is batching-smelting-crushing powder-making-hot pressing sintering-target processing. Due to the need for crushing and powdering during the preparation process, it is difficult to control the impurities of the target content and the distribution uniformity of each component, and because of the large size of the target, it is easy to have a temperature difference during the hot pressing sintering process, which will lead to defects such as phase separation and cracking of the alloy target

With the demand of semiconductor technology, the requirements for the size of the target are getting bigger and bigger, and the requirements for the content of impurity oxygen are becoming more and more stringent. Due to the requirements of purity and uniformity, it is urgent to invent a new technology to prepare low-oxygen large-size alloy targets

Images