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We report a method for the directed self-assembly (DSA) of block copolymers (BCPs) in which a first BCP film deploys homopolymer brushes, or "inks", that sequentially graft onto the substrate's surface via the interpenetration of polymer molecules during the thermal annealing of the polymer film on top of existing polymer brushes. By selecting polymer "inks" with the desired chemistry and appropriate relative molecular weights, it is possible to use brush interpenetration as a powerful technique to generate self-registered chemical contrast patterns at the same frequency as that of the domains of the BCP. The result is a process with a higher tolerance to dimensional and chemical imperfections in the guiding patterns, which we showcase by implementing DSA using homopolymer brushes for the guiding features as opposed to more robust cross-linkable mats. We find that the use of "inks" does not compromise the line width roughness, and the quality of the DSA as a lithographic mask is verified by implementing a robust "dry lift-off" pattern transfer.

With the technological development and progresses of the semiconductor industry， chip manufacturing is stepping forward to the advanced technology nodes under the impetus of Moore's Law. Meanwhile，the corresponding advanced materials for lithography are highly desired to satisfy the rapid development of advanced lithographic patterning. This review focuses on the composition and performances of materials for lithography. The photoresist from ultraviolet，deep ultraviolet，and extreme ultraviolet light as well as semiconducting photoresist and materials for directed self-assembly （DSA） are systematically summarized. Subsequently，the current market development and requirement of materials for lithography are critically examined. Finally，after a brief summary，an outlook for the prospective studies on advanced materials for lithography and the corresponding solutions to improve the domestic market occupancy is provided [ABSTRACT FROM AUTHOR]

Resistive electrical test structures have been designed to enable the characterization of optical proximity correction (OPC) applied to a right-angled corner in a conducting track. The OPC consists of square serifs that are either added to the outside corner or subtracted from the inner corner. Varying degrees of OPC can be applied by changing the size of the square serif or by changing the amount by which it encroaches on or protrudes from the corner. A prototype test mask has been fabricated that contains test structures suitable for on-mask electrical measurement. The same mask was used to print the test pattern in polysilicon and aluminium using an i-line lithography tool and results from these structures clearly show that OPC has an impact on the resistance of the final printed features. In particular, the level of corner rounding is dependent upon the dimensions of the serifs employed and the measured resistance can be used to characterize the effects of different levels of OPC applied to the inner corners. [ABSTRACT FROM PUBLISHER]

For bit patterned media (BPM) applications, while significant progress has recently been made in demonstrating high-resolution dot patterning using e-beam direct writing, and followed by the successful imprint process, many serious issues in fabrication still remain. This paper will only discuss the key challenges in the BPM lithography, including 1) the commercial availability of a high-resolution rotating stage e-beam system; 2) the approach and limitation of directed polymer self-assembly for resist pattern quality improvement and resolution enhancement; 3) the difficulties and limitations in the fabrication and replication of a 1 x template with a density beyond 1 Tbit per square inch (Tb/in2), while the defectivity, lifetime, and damage of the template are still questionable; 4) the tight requirements of size uniformity and placement accuracy; and 5) the needs of advanced metrology associated with the very small dot size and defect characterization. In this paper, we will address the above challenges and present some experimental data along with possible solutions for the challenges. [ABSTRACT FROM AUTHOR]

This paper compares electrical, optical, and atomic force microscope (AFM) measurements of critical dimension (CD) made on a chrome on quartz photomask. Test structures suitable for direct, on-mask electrical probing have been measured using the above three techniques. These include cross-bridge linewidth structures and pairs of Kelvin bridge resistors designed to investigate dimensional mismatch. Overall, the results show very good agreement between the electrical measurements and those made with a calibrated CD-AFM system, while the optical metrology system overestimates the measured width. The uncertainty in each of the measurements has been considered, and for the first time an attempt has been made to describe the levels and sources of uncertainty in the electrical measurement of CD on advanced binary photomasks. [ABSTRACT FROM AUTHOR]

This paper presents a comparison of optical and electrical techniques for critical dimension (CD) metrology on binary and alternating aperture phase-shifting masks. Measurements obtained from on-mask electrical CD structures are compared with optical measurements made using a deep ultraviolet mask metrology system. The results show that the presence of alternating phase-shifting trenches between the chrome blocking features has a detrimental effect on the optical measurements and that this effect strongly depends on the depth of the trenches. In addition, the optical metrology system appears to have problems with the measurement of the narrowest isolated features due to calibration related issues. Electrical CD measurements are seen as a way of probing the limits of optical tool calibration and for highlighting and managing the need to extend the complexity of the calibration schedule. [ABSTRACT FROM AUTHOR]