Gary Van Schooneveld, CT Associates, Inc., Minnesota, USA

ABSTRACT

The reduction in semiconductor device critical dimensions puts pressure on the suppliers of fluid handling components and systems to continuously reduce their contamination contribution.  The ITRS’ (International Technology Roadmap for Semiconductors) critical particle dimension for a number of devices is below the detection limit of commercially available particle counting instruments.  Industry standard test methods such as SEMI F57 and F40 have not necessarily kept up with the requirements being identified by the ITRS and end users. 

Sang Hyun Park, Oerlikon Leybold Vacuum, USA

ABSTRACT 

It is remarkable that vacuum-based processes used to produce low density/large scale devices have also been used for controlling and making devices in high density processes utilizing some of the smallest scales humans have ever made.  People involved in science, materials, semiconductor, flat panel displays (FPDs), and research and development have preferred the use of vacuum processes to non-vacuum processes, the advantages of which are outlined below. There are different ways to analyze processes at process chambers and along vacuum lines depending upon your point of interest.  The general approach will be to look at the materials point of view (chemistry of materials), control of energy point of view and vacuum point of view to better understand the process characteristics that will result in improved tool uptime.  Depending upon the purpose of your process analyses, one aspect can be more important than the rest.  This article will be focused on how to evaluate the chemistry and materials of processes and cleaning with vacuum at the chamber(s) and along vacuum lines.

By William Glime, Swagelok Company, USA, and Thomas Seidel, Genus, Inc., USA

ABSTRACT

High-productivity Atomic Layer Deposition (ALD) processes are being driven by semiconductor applications (e.g., capacitor, gate and interconnects) requiring ultra-thin films or conformal coatings with precise thickness control. ALD is particularly effective on surfaces with high aspect ratios or where graded compositions (i.e., where one layer consists of one material and the next layer of another) are required.  Future memory devices referenced in the International Technology Roadmap for Semiconductors (ITRS) - such as Magnetic RAM (MRAM) and Phase Change Memories, Nanofloating Gates, Single-Electron and Molecular Memories - may initially employ topologies with relatively relaxed aspect ratios, as compared to today’s DRAM devices. However, they all require ultra-thin films, and eventually, they will all migrate toward moderate, if not extreme, aspect ratios. The ITRS projects that DRAM capacitor deep trenches made circa 2010 will require step coverage on high aspect ratios approaching 100:1 at 45nm sizes. The active area would be 20× the planar silicon. The challenge to provide conformal coating on such high-density structures will depend on significant advances over conventional ALD, including advances in ALD chemical precursors, delivery systems, and operating systems. 

Alan Levine, Jasen Sanders, CA, USA

ABSTRACT

The use of new ultrapure poly silicon furnaceware has a dramatic impact on the cost of ownership for the entire LPCVD polysilicon process. Benefits are demonstrated in cost reduction and increased productivity. Further benefits are demonstrated for yield, which is quantified in cost of ownership as a change in scrap costs. Sensitivity analysis allows these results to be extrapolated to a wide range of situations.

By Bipin Parekh, Michael Clarke, Anni Xia and Joseph Smith, Entegris, USA

ABSTRACT

Driven by increasing consumer demand, semiconductor manufacturers have increased chip capacity at staggering rates using optical lithography by shrinking the circuit line widths.  To print these finer lines, manufacturers have relied on a progressively smaller wavelength light source, which currently is 193nm laser targeted to the 65nm features.  In order to extend the 193nm illumination beyond 65nm, semiconductor manufacturers are gearing up for a transition from dry lithography to a processing technique, Immersion Lithography, using ultra-pure water (UPW). 

Discussion panel contributors include: Dr. Vivek Bakshi, SEMATECH, Austin, Texas, USA, Dr. Martin McCallum, Manager, Advanced Lithography and Technology, Nikon Precision Europe GmbH, & Dr. Vadim Banine, ASML, Veldhoven, The Netherlands

ABSTRACT

Significant improvements in EUV light sources have been made in the last 12 months, resulting in renewed hope that one of several key barriers to the eventual adoption of EUV as the mainstream lithography technology below the 32nm node may be close to being overcome. Development work has been carried out around the world and within key working groups. We asked some of these groups to provide insight into what has been achieved and what is still needed to be done before EUV lithography shows the light of day!

Mark Osborne, Semiconductor Fabtech, Editor-in-Chief

Andreas Neuber, M+W Zander , Germany

ABSTRACT

High purity polymer piping and components are used extensively in semiconductor manufacturing facilities for process chemicals, slurries and ultrapure water.  Polymer piping materials are chosen because of their low leachout of metals and lower installation costs.  In the last ten years the main high purity materials used in fabs are PVDF for ultrapure water and PFA for acids, caustics, oxidizers as well as corrosive solvents with the secondary containment for chemical lines being clear PVC or stainless steel for flammable process liquids.  However, cost pressure is continuously increasing in the highly competitive semiconductor industry.  This has required value engineering efforts to be undertaken to explore whether other materials can be used for specific applications.  This paper provides an overview of current purity requirements in state-of-the-art fabs and what factors need to be considered in selection of alternative polymer materials for the most cost effective solution in the design, construction and operation of wafer fab facilities.  Specific characteristics of different polymer materials are discussed and applied to the range of purities required in this industry. 

Sunniva Collins, Ph.D, Swagelok Company, Solon, Ohio, USA

ABSTRACT

SEMI F78 and F81, together with revisions to F20, represent important steps in the evolution of the semiconductor industry. Contamination and corrosion are issues of great concern in the semiconductor industry - and they will remain so, as line widths continue to shrink and new processes are brought on line. Gas Tungsten Arc (GTA) welding involves practices and procedures - variables - in the equation. A systematic, standardized approach, as outlined in new SEMI standards, ensures that human error is held to a limit and unsuccessful welds are understood as the result of specific, identifiable variables. The SEMI standards concerning GTA welding are useful and specific, and are intended to improve outcomes in everyday applications. 

Kevin Pate, Intel Corporation, Oregon, USA

ABSTRACT

Trace metal contamination in process chemicals can detrimentally affect performance of the electronic device on the wafer. Bulk chemical delivery systems use ‘high purity' plastics (generally PFA based) for distribution system tubing, valves, fittings, and vessels to enable clean delivery of process chemicals to wafer processing tools. This trace metals extraction (leaching) study determined the amount and rate that trace metals diffuse out of PFA plastics into process chemicals over time. The study also determines whether transition to higher purity PFA resins will be required in the near future to meet increasingly stringent purity requirements for the wafer manufacturing process.

Jon Owyang, Jeff Bailey & Subrata Chatterji, Aviza Technology, Inc., CA, USA

ABSTRACT

Fundamentally,atomiclayer deposition (ALD) is a straightforward and tolerant deposition technique. Most chemical vapor deposition (CVD)  reactors (i.e. batch and single wafer) can be modified to deposit materials in an ALD mode. However, the critical barriers in making ALD a production-worthy process lies in the challenge of processing films in ALD mode that is quick enough to meet the technical film requirements for uniformity, step coverage, defect density and electrical properties. The design of the liquid/gas delivery/distribution system, the chamber and exhaust mechanism are the key differentiators between R&D tools vs. high-volume manufacturing tools. 

James M. Hanson, Swagelok Company, Ronnie A. Browne & Robert A. Shutler, Swagelok Semiconductor Services Company, Santa Clara, California, USA

ABSTRACT

New wet processes for semiconductor manufacturing, employing slurries, as well as HCl and HF at higher pressures and temperatures, are requiring higher standards for purity and improved design and materials for fluid-system components. OEMs, toolmakers and integrators are calling for longer life cycles, easier maintenance, resistance to permeation and reduced particle shedding in valves and other system components. 

Martin Bijker, OTB-Solar, Eindhoven, Netherlands, Chistopher M. Rippl & Frank Klabunde, Pfeiffer Vacuum GmbH, Asslar, Germany

ABSTRACT

OTB-Solar, a manufacturer of solar cell coating systems has developed a new type of SiN anti-reflection coating system DEPx (see Figure 1).In this system three load-lockchambers are necessary. In the past it was necessary to equip these loadlock chambers with a combination of a turbopump and a backing pump to reach the specifications. This led to a high installation effort with three valves, a bypass for the turbopump and complex system software to control this vacuum system. 

Mark Osborne, Editor-in-Chief, Semiconductor Fabtech

ABSTRACT

The migration to 300mm sized wafer's became a reality with the move to standards driven nonmanual wafer handling, which saw a new type of sub-system being created. A typical 30,000 wafer starts per month (wspm) 300mm fab has over 300 tools and over 400 process steps putting huge demands on the wafer handling systems to provide fast and reliable transportation. However, the industry has experienced problems that have limited factory performance and overall production efficiencies. We take a look at a second generation of automated sub-systems for EFEM and wafer sorter functions, which promise to take 300mm fab operations to the next level. 

Brad Stimson & Alan Ritchie, Applied Materials, Inc., Santa Clara, CA, USA

ABSTRACT

Physical Vapor Deposition (PVD) systems are among the most widely used systems in fabs. To extend PVD technology, a highly successful platform has been redesigned to meet sub-90nm requirements. Over 14 years of being used in production (which continues till today), vast modifications were made to both the PVD mainframe unit and its chambers to keep abreast of ever changing design nodes and device designs. 

David J. Hilton, Busch Semiconductor Vacuum Group, Morgan Hill, CA, USA

ABSTRACT

In times past, semiconductor vacuum processing was typically done with "oilsealed" wet rotary vane, or rotary piston-type vacuum pumps. Variations of the actual operation of these types of pumps were not so great that substitution from one manufacturer to the next was not difficult. With today's modern dry vacuum pumps, this is no longer the case. Over the past decade or so, there have been several different types of these dry vacuum pumps, designed and manufactured, which have very striking differences in mechanical design. 

Gerhard Schiroky & Gary Henrich, Swagelok Company, Solon, Ohio, USA

ABSTRACT

A study was performed to determine the corrosion behavior of welded tube samples of ultralow-manganese and low-manganese 316L alloys in corrosive gaseous environments. First, a weld-fume analysis was performed to determine which elements evaporate to a significant extent during orbital welding with 316L test samples containing different amounts of manganese. Second, welded tube sections were exposed to corrosive gases and the surfaces were characterized by scanning electron microscopy (SEM) both in the short term (24 h) and in the long term (28 days). It has been claimed that during welding, the manganese evaporates from the weld pool and redeposits in the heat-affected zone, primarily downstream of the weld pool, causing corrosion to occur. 

Giuseppe Fazio & Massimo Strada, ST Microelectronics, Central R&D, Agrate Brianza, Italy

ABSTRACT

In the modern fab process control is very important. The process control may be improved by modifications to equipment. The wafer-cleaning process is one of the most important and critical steps in semiconductor manufacturing. In this process two or more chemicals are mixed and it is very important to have the correct concentrations. Repeatability and reproducibility in concentration impact on the process quality. The chemical input usually is guaranteed by mechanical flow controllers installed in every chemical line, where a narrowing regulated by a valve provides the correct flows entering the DIW line. The performance of such flow controllers is affected by several variables: chemical pressure or DIW flow, which could generate fluctuations during the chemical injection phase.

Mark Osborne, Editor-in-Chief, Semiconductor Fabtech

ABSTRACT

Atomic Layer Deposition (ALD) has long been hailed as a next generation technology, enabling semiconductors to enter the nanoworld that promises to keep pace with the demands of Moore's Law. Only in the last two years has this technology moved from the lab into the fab. The pace of adoption is expected to increase significantly at the 70nm node for DRAM and the 65-45nm nodes for logic. ALD is a variant of chemical vapor deposition (CVD) and therefore requires reactor and reactor-related components for operation under controlled vacuum conditions.