Infineon Technologies Ag

Globalfoundries Inc.

Francis Goodwin

Lei Sun

Obert Reeves Wood, Ii

Yulu Chen

Genevieve Beique

Jed Hickory Rankin

Nicholas V Licausi

Erik A Verduijn

Stefan Brandl

Erik Verduijn

Brian Martinick

The present disclosure relates to semiconductor structures and, more particularly, to an extreme ultraviolet (EUV) lithography mask and methods of manufacture. The EUV mask structure includes: a reflective layer; a capping material on the reflective layer; a buffer layer on the capping layer; alternating absorber layers on the buffer layer; and a capping layer on the top of the alternating absorber layers.

Extreme ultraviolet (EUV) lithography mask

The disclosure is directed to methods of identifying a space within an integrated circuit structure as a mandrel space or a non-mandrel space. One method may include: identifying a space between freestanding spacers as being one of: a former mandrel space created by removal of a mandrel from between the freestanding spacers or a non-mandrel space between adjacent mandrels prior to removal of the mandrel, based on a line width roughness of the space, wherein the line width roughness represents a deviation of a width of the space from a centerline axis along a length of the space.

Methods of identifying space within integrated circuit structure as mandrel space or non-mandrel space

Extreme ultraviolet mirrors and masks used in lithography and methods for manufacturing an extreme ultraviolet mirror or mask. Initial data is obtained that includes materials and optical properties for a first intermixed layer, a second intermixed layer, a first pure layer, and a second pure layer in each of a plurality of periods of a multi-layer stack for an optical element. For multiple thicknesses for the first pure layer and multiple thicknesses for the second pure layer, a reflectivity of the multi-layer stack is determined based on the initial data, a thickness received for the first intermixed layer, and a thickness received for the second intermixed layer. One of the thicknesses for the first pure layer and one of the thicknesses for the second pure layer are selected that maximize the reflectivity of the multi-layer stack.

Extreme ultraviolet mirrors and masks with improved reflectivity

Fluids for use in immersion lithography systems are disclosed. A resistivity-altering substance is introduced into a fluid, making it more conductive. The fluid is then disposed between an immersion head of a projection lens system and a semiconductor wafer during an exposure process. Because the fluid is conductive, electrostatic energy that may develop during the movement of the semiconductor wafer with respect to the projection lens system during the exposure process is discharged through the conductive fluid, preventing damage to an immersion head of the projection lens system, the semiconductor wafer, and sensors of a stage that supports the semiconductor wafer.

Fluids for immersion lithography systems

A closing disk for an immersion head of an immersion lithography system is disclosed. The closing disk makes contact with the immersion head at the edges of the closing disk, but not the center, preventing damage to the bottom surface of the immersion head and also to the closing disk. The closing disk may be transparent or opaque, and may be aligned to the immersion head using optical or mechanical alignment.

Closing disk for immersion head

From a plurality of overlay targets formed with patterns on a test wafer, subsets are formed and for each overlay target contained in the subsets, the measurement results of overlay shifts are obtained. Mean shifts, residual data and ranges are calculated for each subset and compared with the 100% full field results. The subset that represents the full field results to highest agreement is selected and used to measure the overlay of a second or any further wafer. A most preferred embodiment relates to selecting each of the subsets in a form such that the overlay target positions are concentric about the wafer center. In a further advantageous aspect, each of the subsets is confined to concentric areas about the wafer center, e.g., an inner circle and/or one or more outer rings. A distribution of selected overlay targets placed in representative regions on the wafer is thus guaranteed.

Growing community of inventors

Halfmoon, NY, United States of America

Francis Goodwin