Plasma surface processor atomic layer etching technology

• Categories:Technical Support
• Author:plasma cleaning machine-surface treatment equipment-CRF plasma machine-Sing Fung Intelligent Manufacturing
• Origin:
• Time of issue:2020-11-30
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(Summary description)With the decreasing of device size, semiconductor manufacturing industry has gradually entered the stage of atomic scale. Over the next 10 years, the acceptable range of characteristic size changes will be required to be within the order of three to four silicon atoms. The non-uniformity of device size will greatly affect the stability, leakage current and battery power loss of the whole device, resulting in device failure and yield reduction. In order to control the etching process accurately and improve the etching result, the atomic layer etching technique has been developed and studied. Although atomic-layer etching has been reported for more than 20 years, its rate of etching is relatively slow compared with traditional etching, and the low yield of etching process restricts its application in semiconductor manufacturing industry. However, with the development of three-dimensional structure fin-transistor technology, the homogeneity of atomic layer etching technology and the selection of ultra-high, plasma surface processor has been applied well in some key etching processes.   The atomic-layer etching technique of plasma surface processor (PSMP) is considered as a promising method to realize etching at atomic level, which is due to its self-limiting behavior. Self-limiting behavior means that the etching rate gradually slows to a stop with the increase of etching time or reactant input. An ideal atomic layer etching cycle can be divided into the following four stages: (1) inject reaction gas into the cavity, modify the surface of the material to form a single layer of self-limiting layer; (2) stop the reaction gas, and vacuum pump to remove the excess gas did not participate in the reaction; (3) High-energy particles are injected into the cavity to remove the single-layer self-limiting layer so as to realize self-limiting etching behavior; (4) Stop feeding high-energy particles, use the plasma surface treatment machine vacuum equipment pump to remove excess particles and etching by-products not involved in the etching.   For each cyclic reaction A and B in the actual atomic layer etching process, the ideal single-layer self-limiting etching process is difficult to be realized. Reaction A includes four different surface modification mechanisms, namely, chemisorption, deposition, conversion, and stripping. Reaction B mostly needs plasma assistance, and ions are used for anisotropic etching to obtain the etching structure with high aspect ratio. Plasma surface processors have been developed from atom etching to date and have been proven to be suitable for more than 20 different materials, including semiconductors, insulators and metals. It is believed that in the near future, it will be applied to more materials etching.