Dian Sugiarto

Feasibility of a CVD-resist-based lithography process at 193-nm wavelength

Thin layer imaging can extend the optical lithography limit down to sub-0.18 micrometers CD with 193 nm wavelength tools. Thin layer imaging can be implemented in a bi-layer approach, in which a patterned thin layer is transferred into an underlying organic planarizing layer. It can also be implemented in a single-layer hardmask process, in which a photodefineable oxide precursor is used to directly pattern a device layer. In the first portion of our study, a plasma polymerized methyl silane (PPMS) bi-layer baseline process has been characterized for photospeed, resolution, and line edge roughness (LER). 1500 angstroms thick organosilane films were patterned by a photo-oxidation process using a 193 nm stepper (NA equals 0.6). The process exhibits photospeeds that are easily tuned from 40 to 100 mJ/cm2 in a well-controlled manner by adjusting the PPMS CVD deposition parameters. The process has demonstrated a resolution of 0.13 micrometers . We show that the total dry-develop process time is critical in determining the lithographic process latitude, photospeed, resolution and LER characteristics. The CVD resist process is most attractive if the thin layer can be directly converted into a thin oxide hard mask, useful for transferring the pattern directly into an underlying device layer. We demonstrate a CVD photoresist process in which patterned PPMS is converted into a silicon dioxide hardmask, and then transferred into underlying amorphous-Si layers with high sensitivity. Using this technique, we have successfully demonstrated 0.15 micrometers resolution amorphous-Si lines.

Application of plasma-polymerized methylsilane for 0.18-μm photolithography

Plasma polymerized methylsilane resist films (PPMS) have high sensitivity to short wavelength radiation. The photoinduced oxidation of PPMS films exposed in air forms siloxane network material (called PPMSO), allowing dry development by selective etching of the unexposed regions upon treatment with chlorine based plasmas. Negative-tone patterns of oxidized methylsilane thus formed can be consolidated in a standard resist stripper to form SiO2 like hard mask patterns. In this work, PPMS films are deposited using a commercial single wafer cluster tool dedicated to dielectric deposition. After exposure at 248 or 193 nm, PPMS development is performed in a commercial high density plasma source etcher. Oxide patterns obtained from PPMS films are used for organic resist patterning (bi-layer application) and gate stack patterning (single layer application).

Single layer chemical vapor deposition photoresist for 193 nm deep ultraviolet photolithography

The chemical vapor deposition resist film plasma polymerized methyl silane (PPMS) can be used as a single layer photoresist for optical lithography at 248 and 193 nm wavelengths. Upon exposure, the PPMS undergoes efficient photo oxidation in the presence of air to yield a siloxane network (PPMSO) giving patterns that can be dry developed using a chlorine-HBr plasma. After dry development, the PPMSO can be used to transfer a pattern through organic low κ materials, or can be converted to a silicon dioxide hardmask using a conventional resist stripper, then used to transfer patterns into polysilicon.

Multi-generation CVD low /spl kappa/ films for 0.13 /spl mu/m and beyond

After several delays in the implementation of /spl kappa/<3.0 inter metal dielectric, the semiconductor industry has finally begun to use these low /spl kappa/ materials in manufacturing in 2001. After several years of intense industry wide evaluation and assessment, the most critical requirements for these materials were identified to be high mechanical strength, low cost, high productivity and extendibility to at least another generation. CVD low /spl kappa/ films, IMD film black diamond (BD) and barrier/etch stop film BLO/spl kappa/, have become the materials of choice for 0.13 /spl mu/m an below generation IMD because of their silicon oxide like materials properties, proven manufacturability using time-tested familiar PECVD tool sets, and the recently proven extendibility to /spl kappa/<2.5. This paper focuses on the characteristics and performance of these materials both in Cu damascene integration and in production environment.

Progress of a CVD-based photoresist 193-nm lithography process

Plasma polymerized organosilane resists films have been shown to exhibit high sensitivity to DUV radiation. We have previously demonstrated a 193nm CVD photoresist process in which plasma polymerized methylsilane (PPMS) is patterned via photo-oxidation, dry-developed, converted into silicon dioxide, and then transferred into an underlying Si layer with high selectivity. The PPMS resist exhibits linearity down to a resolution of 130 nm L/S for a 1:1 pitch. We have demonstrated 100 nm Iso-lines at 28 mJ/cm2 dose with 11 percent dose latitude and 600 nm focus latitude. Depths of focus greater than 500 nm have been demonstrated for 160 nm nested L/S.