Taiwan Semiconductor Manufacturing Comp. Ltd.

Chen-Shao Hsu

Shih-Ming Chang

Hsin-Chang Lee

Chia-Jen Chen

Tran-Hui Shen

Chien-Cheng Chen

Yen-Cheng Ho

Chien-Chih Chen

Chih-Chiang Tu

Chun-Lang Chen

Jong-Yuh Chang

Yen-CHeng Ho

In a method of manufacturing a photo mask for lithography, circuit pattern data are acquired. A pattern density, which is a total pattern area per predetermined area, is calculated from the circuit pattern data. Dummy pattern data for areas having pattern density less than a threshold density are generated. Mask drawing data is generated from the circuit pattern data and the dummy pattern data. By using an electron beam from an electron beam lithography apparatus, patterns are drawn according to the mask drawing data on a resist layer formed on a mask blank substrate. The drawn resist layer is developed using a developing solution. Dummy patterns included in the dummy pattern data are not printed as a photo mask pattern when the resist layer is exposed with the electron beam and is developed.

Method of manufacturing photo masks

In some embodiments, a mask patterning system includes an electronic memory configured to store an integrated circuit mask layout. A computation tool determines a number of radiation shots to be used to write the integrated circuit mask layout to a physical mask. The computation tool also determines a scaling factor which accounts for expected thermal expansion of the physical mask due to the number of radiation shots used in writing the integrated circuit mask layout to the physical mask. An ebeam or laser writing tool writes the integrated circuit mask layout to the physical mask based on the scaling factor and by using the number of radiation shots.

Mask overlay control

Some embodiments of the present disclosure relate to a method of patterning a workpiece with a mask, wherein a scale factor between a geometry of the mask and a corresponding target shape of the mask is determined. The scale factor results from thermal expansion of the mask and geometry due to heating of the mask during exposure to radiation by an electron beam (e-beam) in the mask manufacturing process. A number of radiation pulses necessary to dispose the geometry on the mask is determined. A scale factor for the mask is then determined from the number of pulses. The target shape is then generated on the mask by re-scaling the geometry according to the scale factor prior to mask manufacturing. This method compensates for thermal deformation due to e-beam heating to improve OVL variability in advanced technology nodes.

Some embodiments relate a method of forming a photomask for a deep ultraviolet photolithography process (e.g., having an exposing radiation with a wavelength of 193 nm). The method provides a mask blank for a deep ultraviolet photolithography process. The mask blank has a transparent substrate, an amorphous isolation layer located over the transparent substrate, and a photoresist layer located over the amorphous isolation layer. The photoresist layer is patterned by selectively removing portions of the photoresist layer using a beam of electrons. The amorphous isolation layer is subsequently etched according to the patterned photoresist layer to form one or more mask openings. The amorphous isolation layer isolates electrons backscattered from the beam of electrons from the photoresist layer during patterning, thereby mitigating CD and overlay errors caused by backscattered electrons.

Mask blank for scattering effect reduction

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Huatan, Taiwan

Chen-Shao Hsu