*Article* **High-Precision Regulation of Nano-Grating Linewidth Based on ALD**

**Yaxin Zhang 1,2,†, Chenying Wang 1,3,\* ,†, Weixuan Jing 1,2,\*, Song Wang 1,2, Yujing Zhang 1,2, Liangliang Zhang 1,2 , Yijun Zhang <sup>4</sup> , Nan Zhu 1,2, Yunxiang Wang <sup>5</sup> , Yifan Zhao 1,4,\*, Qijing Lin 1,3 and Zhuangde Jiang 1,2,3**


**Abstract:** A nano-grating standard with accurate linewidth can not only calibrate the magnification of nano-measurement instruments, but can also enable comparison of linewidths. Unfortunately, it is still a challenging task to control the linewidth of nano-grating standards. Accordingly, in this paper, atomic layer deposition (ALD) was used to regulate the linewidth of the one-dimensional grating standards with a pitch of 1000 nm, fabricated by electron beam lithography (EBL). The standards were measured using an atomic force microscope (AFM) before and after ALD, and the linewidth and pitch of the grating were calculated through the gravity center method. The obtained results prove that the width of a single grating line in the standard can be regulated with great uniformity by precisely utilizing ALD. Meanwhile, the proposed method does not affect the pitch of grating, and the measurement uncertainty of standards is less than 0.16% of the pitch, thereby demonstrating a high surface quality and calibration reliability of the standards, and realizing the integration of linewidth and pitch calibration functions. Moreover, the precise and controllable fabrication method of the micro-nano periodic structure based on ALD technology has many potential applications in the fields of optoelectronic devices and biosensors.

**Keywords:** atomic layer deposition (ALD); linewidth regulation; micro- and nano-metrology; one-dimensional nano-grating standard
