**7. References**


**17** 

*China* 

**Emerging Maskless Nanolithography Based** 

*1College of Electronic Science and Technology, Shenzhen University, Shenzhen,* 

*4Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu,* 

*2Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen,* 

*6Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou,* 

The development of lithographic technology that has been used in semiconductor electronics has led to systems that put a premium on spatial resolution, throughput and reliability, regardless of cost and flexibility. According to Abbe's theory, the spatial resolution can be improved by using either shorter wavelength or higher numerical aperture (*NA*). Although the semiconductor industry has made significant progress in increasing the lithography resolution in the past decades, further improvement of the resolution by accessing shorter wavelengths is facing critical challenges due to the availability of optical materials with suitable refractive index. The expansion of nanoscale science and engineering will require flexible, high spatial resolution, and low-cost nanolithographic techniques and systems other than those employed in the semiconductor industry, for reasons of both cost and limited flexibility. The research on Emerging Maskless Nanolithography Based on Novel Diffraction Gratings presented in this chapter is a step in the direction of providing

In this chapter, we present two cases for maskless nanolithography employed novel diffraction optics elements as objective lens to focus illumination light. The diffractive objective lens (DOL) operates by the principle of diffraction other than conventional objective lens functioning by refraction. DOL can be designed to operate at any wavelength while refractive elements are constrained at short wavelengths by material transmission properties. DOL are thinner, and can be fabricated by planar techniques that are reliable and

DOL, in a form of photon sieves originally used in x-ray microscopy and achieved 6nm resolution, is possible to extend the use of diffractive elements down to the limits of nanolithography. Recently, we present the scheme of photon sieve array X-ray maskless nanolithography (PSAL) to fabricate novel nanometer devices (Cheng et al., 2006, 2007a, 2007b, 2008). The lithographic principle is shown in figure 1. Firstly, each of the photon sieve

**1. Introduction** 

low cost.

affordable, highly flexible nanolithography.

**on Novel Diffraction Gratings** 

*3The Chinese University of Hong Kong, Hong Kong,* 

Guanxiao Cheng1,2,3, Yong Yang4, Chao Hu2,3,5, Ping Xu1, Helun Song6, Tingwen Xing4 and Max Q.-H. Meng2,3

*5Ningbo Institute of Technology, Zhejiang University, Ningbo,* 

