THERMALLY STABLE ALIGNMENT MARK FOR ELECTRONIC LITHOGRAPHY Russian patent published in 2021 - IPC H01L21/18 G03F1/20 

FIELD: microelectronics.

SUBSTANCE: invention relates to microelectronics technology, namely, to the technology of forming GaN transistors for various purposes (high-power and microwave transistors) and, in particular, to the creation of thermally stable alignment marks suitable for electronic lithography and photolithography. To ensure high intensity and low blurring of the reflected electron flux after performing technological operations at temperatures in the range of 800-1000ºC, as well as to reduce the cost of the technological process, a hafnium-based mark design is proposed. The mark consists of two layers of metals: molybdenum (Mo) with a thickness of up to 50 nm and hafnium (Hf) with a thickness of 50-100 nm.

EFFECT: use of a molybdenum sublayer improves the adhesion of the alignment marks to the surface of the heterostructure, and the high melting temperatures of the metals used ensure the preservation of the shape and morphology of the marks during the heat treatment of the substrate.

1 cl, 2 dwg