Majumder Apratim, Masid Farhana, Pollock Benjamin, Andrew Trisha L, Menon Rajesh
Opt Express. 2015 May 4;23(9):12244-50. doi: 10.1364/OE.23.012244.
Absorbance-Modulation-Optical Lithography (AMOL) enables super-resolution optical lithography by simultaneous illumination of a photochromic film by a bright spot at one wavelength, λ1 and a node at another wavelength, λ2. A deep subwavelength region of the transparent photochromic isomer is created in the vicinity of the node. Light at λ1 penetrates this region and exposes an underlying photoresist layer. In conventional AMOL, a barrier layer is required to protect the photoresist from the photochromic layer. Here, we demonstrate barrier-free AMOL, which considerably simplifies the process. Specifically, we pattern lines as small as 70nm using λ1 = 325nm and λ2 = 647nm. We further elucidate the minimum requirements for AMOL to enable multiple exposures so as to break the diffraction limit.
吸收调制光学光刻（AMOL）通过在一个波长λ1处用亮点同时照射光致变色膜以及在另一个波长λ2处用节点照射光致变色膜，实现了超分辨率光学光刻。在节点附近会形成透明光致变色异构体的深亚波长区域。波长为λ1的光穿透该区域并曝光下层光刻胶层。在传统的AMOL中，需要一个阻挡层来保护光刻胶免受光致变色层的影响。在此，我们展示了无阻挡层的AMOL，这大大简化了工艺。具体而言，我们使用λ1 = 325nm和λ2 = 647nm光刻出了小至70nm的线条。我们进一步阐明了AMOL实现多次曝光以突破衍射极限的最低要求。
