摘要:

This article presents experimental results on the temperature rise in x‐ray masks and the temperature‐induced distortions printed on wafers during scanning synchrotron radiation exposure. It also presents theoretical analyses confirming the validity of the experiments. The temperature rise was measured with an infrared camera and the resultant thermal distortions were quantified by measuring the displacements of patterns printed on wafers. The theoretical simulations were performed using the finite element method. Results of experiments and simulations agree and indicate that even for exposures in air the temperature‐induced distortions are rather small.

ISSN:0734-211X    

DOI:10.1116/1.587424

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

We have studied temperature uniformity during the post‐exposure bake process across a 40 mm diameter of an x‐ray mask membrane. Membrane temperature was determined by measuring line size as a function of position across the membrane. A two‐dimensional finite element model (FEM) was used to analyze the results and optimize the design of a new bake chuck. The 3σ variation across the diameter of the mask was reduced to 27 nm. The FEM was also used to examine issues associated with resist baking on the ARPA‐NIST X‐ray Mask Standard and the initial results are discussed.

ISSN:0734-211X    

DOI:10.1116/1.587425

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

From an image formation point of view, the design of x‐ray masks has been optimized for realistic exposure systems using synchrotron radiation. The analysis has then been carried forward to study the effect of environmental factors such as vibrations. We conclude that the ideal x‐ray mask is based on thin absorbers (0.3–0.4 μm) for Au and W, that the existence of a sidewall slope improves the exposure latitude, and that vibrations (amplitude less than 1/2 critical dimension) do not represent a source of concern. All in all, the x‐ray lithography mask emerges with more relaxed specifications and with a simpler manufacturing process.

ISSN:0734-211X    

DOI:10.1116/1.587426

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

In proximity x‐ray lithography, wavelengths in the range of 4–20 Å are used. The choice of wavelength is a complicated system issue, which depends on many lithographic aspects. Shorter wavelength x rays offer aerial image diffraction advantages. However, they may also give rise to spurious photoelectron effects. Longer wavelength x rays make mask patterning easier since the absorber can have a smaller aspect ratio for the required contrast, but a thinner, less robust membrane is needed to give the same x‐ray transmission. Softer x rays are also better absorbed in resist, reducing the exposure time, but higher absorption can have an adverse effect on the resist sidewall profile. A study is conducted to address the wavelength issue in x‐ray lithography using the exposure window, resist profiles, power efficiency, and the mask contrast as merit/cost functions. Results show that a compromise among these factors is needed to achieve best performance.

ISSN:0734-211X    

DOI:10.1116/1.587427

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

Recent studies have shown that high performance 0.1 μm complementary metal–oxide semiconductor (CMOS) can be achieved with proper channel and source/drain engineering. Specifically, retrograde channel doping and shallow source/drain junctions with counterdoping implant (halo) allow the threshold voltage to be kept low while maintaining acceptable short‐channel behavior. These studies have certainly demonstrated the feasibility of CMOS technology scaled down to 0.1 μm from a device design point‐of‐view. However, the main challenge to the lithography technology is to fabricate 0.1 μm metal‐oxide‐semiconductor field‐effect transistor (MOSFET) devices with high yield and high throughput, as required in manufacturing. X‐ray lithography is a technology that can potentially meet this challenge. This work shows the results of integrating a low cost x‐ray technology with standard IC processing to fabricate high performance 100 nm and even sub‐100 nm MOSFETs.

ISSN:0734-211X    

DOI:10.1116/1.587428

出版商:American Vacuum Society    

年代:1994

数据来源: AIP