A composite multifunctional microstructure which comprises at least one functionalising material associated with a microstructure wherein the microstructure comprises a layer of relief forming material preferably comprising an at least partially UV curable relief forming polymer having a plurality of relief features formed therein to provide at least one retaining feature; and wherein the functionalising material is deposited within and substantially or partially fills or lines the at least one retaining feature, method for the preparation thereof, products of the method and their uses in multifunctional systems.

Multifunctional microstructures and preparation thereof

A pattern writing method for X-ray mask fabrication including forming a uniform membrane layer on an X-ray absorbing layer and forming an etch mask on the layer of X-ray absorbing material including the steps of providing a layer of material sensitive to radiation. The layer of material has internal stresses which are altered by exposure to the radiation. The material is exposed in associated areas (e.g. a spiral) such that the internal stresses within the layer of material and altered internal stresses in the associated areas are substantially offset to reduce distortion in the X-ray mask.

Pattern writing method during X-ray mask fabrication

A charged particle beam writing apparatus includes a shot division unit configured to divide a figure defined in layout data into a plurality of shot figures each having a size which can be irradiated by one shot of a charged particle beam, a shot data generating unit configured to generate each shot data for each shot figure of the plurality of shot figures, where a number of times of generating the each shot data equals a number of times of multiple writing of the each shot figure of the plurality of shot figures, such that multiplicity of the multiple writing is variable per the each shot figure, and a writing unit configured to perform the multiple writing of the each shot figure onto a target workpiece, in accordance with the number of times of the each shot data generated for the each shot figure, using a charged particle beam.

Charged particle beam writing apparatus and charged particle beam writing method

X-ray lithography (XRL) is a patterning technique for the fabrication of semiconductor devices with very small dimensions (≤100 nm). In this process the device and circuit layout images are formed by exposing a thin layer of organic material, the photoresist. XRL is based on the idea that the short wavelength (≈1 nm) of the radiation allows a faithful reproduction of the desired pattern to very small dimensions. The physics of the interaction of the x-rays with matter dictates many aspects of the technique: the imaging process is controlled by Fresnel diffraction, and the recording process by the interaction of low-energy photoelectrons with the resist material. Phase shift effects play a key role in the image formation process, and are used to improve the sharpness of the image. To achieve high-resolution patterning it is necessary to carefully design the pattern itself, and optimize several exposure parameters. This paper presents a detailed discussion of the image formation process, and a brief review of other technical aspects of the technology.

https://iopscience.iop.org/article/10.1088/0022-3727/33/12/201/pdf

X-ray imaging: applications to patterning and lithography

Coated articles and methods for applying coatings are described. The article may include a base material and a coating comprising silver formed thereon. In some embodiments, the coating comprises a silver-based alloy, such as a silver-tungsten alloy. The coating may, in some instances, include at least two layers. For example, the coating may include a first layer comprising a silver-based alloy and a second layer comprising a precious metal. The coating can exhibit desirable properties and characteristics such as durability (e.g., wear), hardness, corrosion resistance, and high conductivity, which may be beneficial, for example, in electrical and/or electronic applications. In some cases, the coating may be applied using an electrodeposition process.

Coated articles and methods

Extreme Ultraviolet Lithography (EUVL) is the leading candidate for next generation lithography. EUVL has good
resolution because of the shorter wavelength (13.5nm). EUVL also requires a new and complicating mask structure. The
blank complexity and substrate polishing requirements result in defects that are difficult to eliminate or repair. Due to
these challenges, shifting the pattern so that absorber covers the multilayer defects is one option for mitigating the
multilayer defect problem. We investigated the capability and effectiveness of pattern shifting using authentic layouts.
The rough indication of, “how many of what size defects are allowable”, is shown in this paper based on the margin for
the 11nm HP pattern. Only the twenty 300nm-sized defects are allowable for current location accuracy of the blank
inspection and writing tools. On the other hand, sixty70nm-sized defects are allowable for the improved location
inaccuracy. Furthermore we exercised the full process for pattern shift using a leading-edge 50 keV e-beam writer to
confirm feasibility and it was successfully performed.

Using pattern shift to avoid blank defects during EUVL mask fabrication

An electrodeposition process for producing gold masks for X-ray lithography of integrated circuits is disclosed. The process produces a gold layer of tightly controlled grain size and arsenic content which results in minimum stress in the gold film and therefore minimum distortion in the features produced from the mask. The process comprises (a) immersing a substrate in a solution containing from 6 to 9 grams of gold per liter and from 8 to 30 mg of arsenite per liter, and (b) passing an electric current having a current density of 1 to 5 mA per cm² through the solution to cause electrodeposition of gold.

Low stress electrodeposition of gold for X-ray mask fabrication

Mask fabrication is one of the difficult challenges with all Next Generation Lithography (NGL) technologies. X-ray, e-beam projection, and ion-beam projection lithography all use some form of membrane mask, and extreme ultraviolet (EUV) lithography uses a reflective mask. Despite some differences, the various mask technologies share some common features and present similar fabrication difficulties. Over the past several years, the IBM Advanced Mask Facility (AMF) has focused on the fabrication of x-ray masks. Several key accomplishments have been demonstrated including fabricating masks with critical dimensions (CD) as small as 75 nm, producing line monitor masks in a pilot line mode to evaluate mask yields, and fabricating masks to make working microprocessors with the gate level defined by x-ray lithography. The experience on fabricating 1X x-ray masks is now being applied to the other NGL mask technologies. Progress on membrane and absorber materials can be applied to all the technologies, and patterning with advanced e-beam writing with chemically amplified resists utilizes learning from writing and baking on x-ray membrane masks.

Next-generation lithography mask development at the NGL Mask Center of Competency

Defects in the EUV mask blank are one of the largest hurdles to achieving manufacturing readiness of EUV masks. For defect-free masks, the obvious approach is to order blanks that do not have defects or to shift the pattern so that remaining defects do not create a printed defect on wafer. The approach during development should be different. At this learning phase, it is wise to study the defects as they occur naturally on the EUV mask blank. This paper outlines a comprehensive approach to building a mask specifically to showcase the native defects so that they can be studied and repairs can be attempted. The method applied to mask build, defect inspection and characterization will be reviewed in detail. Printability of the mask defects of interest are characterized using both wafer printing and EUV microscope data. Repairs are attempted and characterized. In the end, the impact of native defects is discussed along with the viability of various repair methods.

/pdf/learning-from-native-defects-on-euv-mask-blanks-4epxtn35o1.pdf

Learning from native defects on EUV mask blanks

The black border is a frame created by removing all the multilayers on the EUV mask in the region
around the chip. It is created to prevent exposure of adjacent fields when printing an EUV mask on a
wafer. Papers have documented its effectiveness. As the technology transitions into
manufacturing, the black border must be optimized from the initial mask making process through its
life. In this work, the black border is evaluated in three stages: the black border during fabrication,
the final sidewall profile, and extended lifetime studies.
This work evaluates the black border through simulations and physical experiments. The simulations
address concerns for defects and sidewall profiles. The physical experiments test the current black
border process. Three masks are used: one mask to test how black border affects the image
placement of features on mask and two masks to test how the multilayers change through extended
cleans. Data incorporated in this study includes: registration, reflectivity, multilayer structure images
and simulated wafer effects.
By evaluating the black border from both a mask making perspective and a lifetime perspective, we
are able to characterize how the structure evolves. The mask data and simulations together predict
the performance of the black border and its ability to maintain critical dimensions on wafer. In this
paper we explore what mask changes occur and how they will affect mask use.

Steven C. Nash

Papers

Using pattern shift to avoid blank defects during EUVL mask fabrication

Low stress electrodeposition of gold for X-ray mask fabrication

Next-generation lithography mask development at the NGL Mask Center of Competency

Learning from native defects on EUV mask blanks

EUV mask black border evolution