Statement_of_Work.docx

STATEMENT OF WORK

HIGH UNIFORMITY ELECTRON-BEAM DEPOSITION TOOL

Background NASA Goddard Space Flight Center (GSFC) has stringent requirements on the properties of electron-beam-evaporated, thin-metal-film detector elements. Such requirements are met by manufacturing a high-vacuum deposition system for electron beam evaporation with robust, proven methods of meeting the thin film specifications. Requirements for deposited thin-film thickness uniformity, purity, and electrical quality must be met and demonstrably maintainable over many years with good production throughput and minimal maintenance / tool downtime. These elemental thin films are incorporated into x-ray focal planes and are planned for the NASA contribution to the x-ray detector for ATHENA X-IFU (Advanced Telescope for High Energy Astrophysics Integral Field Unit) and other missions and opportunities. Parameters achieved by the thin films are determined by the configurations of the system as well as the performance and durability of the components and mechanisms used in the system. Further, the system must be able to deposit on multiple substrates so that all substrates (also called “wafers”) in a run have resulting metal films with near-identical electronic properties. As such, the vacuum deposition system for e-beam evaporation shall be designed as a production level facility and be optimized for a specific process. Equipment will be designed to meet these specifications in a robust way to simplify maintenance of the process and the equipment and maximize production from the tool.

The thin films needed for NASA GSFC x-ray detector prototypes have several critical parameters that must be met by the equipment prior to acceptance by GSFC. These specifications include uniform thickness across twelve (12) four-inch substrates simultaneously deposited. This uniformity is 1% wafer-to-wafer as well as +/- 2% within the active region of the wafer. If the deposition thickness is expected to depend on material deposited, then the requirement shall be met for elemental gold (Au) film. It must be possible that, during the deposition, the chamber pressure must remain at or below 3e-7 torr to enable film deposition with an acceptable level of incorporation of residual gases. The tool must further be designed to prevent incorporation of the magnetic impurities down to the ppm level into the thin metal films as this is known to degrade the performance of detectors realized from the films.

NASA GSFC has found that thin metal films of gold have desirable properties for x-ray detectors when electron-beam is deposited under proper conditions. Since the process conditions vary slightly from run-to-run, each run must include a substrate to act as a deposition witness. The electronic properties of the thin metal on this substrate need to duplicate the electronic properties on the other substrates as accurately as possible, explaining the need for high uniformity of wafer-to-wafer specifications for wafer deposition conditions and thin film thickness uniformity. For example, variation of film thickness directly impacts variation of device resistance and superconducting transition temperature in a bilayer (two different metals) deposition.

Further, NASA is producing arrays of detectors with a spatial extent of several centimeters. The film thickness uniformity within the wafer must also be kept uniform to keep device parameters uniform within the detector array active area and for having witness arrays produced on the same wafer as the flight array. To achieve the tight film thickness specifications across multiple wafers, a “shaper” plate shall be designed to be installed in the chamber that adjusts the uniformity of the deposition for the selected materials. It is anticipated that the system shall be capable of +/-2% thickness uniformity without the shaper plates and that up to +/-1% becomes achievable with the installation of shaper plates. There shall be a drop in the rate of deposition associated with the installation of the plates.

Other needed capabilities of the system include the ability to deposit several different types of material in the same deposition via electron beam deposition. In addition to elemental aluminum and titanium, the predominant use of the system will be to deposit thin films of ultrapure elemental gold after a brief substrate clean. The system thus requires a low energy ion source for cleaning the substrate with the inert gas argon. Of particular importance is the elimination of all sources of potential magnetic contamination during the ion cleaning, through use of non-magnetic materials in the ion source housing and in the path between the ion source and the wafers. To enable cleaning of the system, two sets of non-magnetic removable shields shall be provided. These shields shall protect the chamber walls and door from deposition and etch and the shields shall be comprised of non-magnetic material (such as Al or Ti). For example, non-magnetic stainless steel is not acceptable because it can be eroded into ferromagnetic materials by the ion clean, creating iron and other contamination in the chamber. The system should be equipped with thickness measurement, wafer temperature measurement, and residual gas analyzer and viewing ports with internal protective covers. The thickness measurement capability shall be shuttered and be multi-channeled so that different materials can be deposited on a dedicated crystal monitor. The system shall feature computer control of the deposition. The system shall be quoted with options for thin metal film depositions on 6” and 8” substrates. The specifications for thickness uniformity of the films on the larger substrates is best effort though the proposer shall indicate what sort of uniformity may be expected.

Objectives Through this statement of work NASA GSFC shall obtain a high vacuum system that achieves specifications for deposition of thin metal films of gold.

The specifications for the vacuum system to be obtained by NASA GSFC include strict limits on the minimum number of substrates, in situ substrate cleaning, thin-film thickness control and uniformity, and deposition conditions. Specifications are as follows:

· The vacuum system shall be capable of deposition on at least twelve 4” silicon wafers and achieve, for each wafer, the film thickness tolerance and other substrate conditions listed here.

· The vacuum chamber shall use a cryopump to achieve a base pressure below 5e-8 torr.

· The vacuum chamber shall maintain a pressure of 3e-7 torr during electron-beam deposition of Au

· The vacuum system shall be capable of electron-beam deposition of films of Au with uniform film thickness (+/-2% across a 100 mm wafer, with 0.5 cm exclusion zone at the edge of the wafer, and +/-1% wafer to wafer).

· A shaper plate (or plates) shall be able to be installed in the chamber to improve the thickness specification beyond the +/-2% level with a goal of +/-1% uniformity.

· The vacuum system shall come equipped with an ion source capable of cleaning a pre-deposited thin film surface without depositing magnetic impurities onto the substrate.

· The vacuum system shall come with non-magnetic, removable shields to protect the chamber walls, doors and ion source from deposition during evaporation.

· The vacuum chamber shall be large enough to be adapted to depositions on 6” and 8” substrates.

The vendor shall provide a deposition tool which is fully cleanroom compatible and compatible with GSFC Class 100 cleanroom facility including compatibility with all provided utilities (power, compressed gases, chilled water) and safety requirements of the GSFC facility.

The vendor shall provide sample depositions on 4” and 8” wafers to verify film thickness uniformity prior to final acceptance of the tool.

The vendor shall install the tool onsite at NASA GSFC.

The vendor shall provide training on the tools once installed at NASA GSFC.

The vendor shall provide one year of support on the tool for achieving the specifications for the thin metal films as quoted by the vendor including improvements as needed to maintain achievement of specifications (if they drift out of spec during the first year).

The vendor shall provide a twelve month warranty on the system for all parts and labor to maintain the functionality of the tool as delivered to and accepted by NASA GSFC.

Scope

The vendor shall design the vacuum system to meet the specification described in the “Objectives” and “Requirements” sections of this statement of work.

The vendor shall provide detailed and complete documentation of the design of the vacuum system to the NASA GSFC technical representative to gain approval of the design prior to build.

The vendor shall proceed with the build after receiving approval from the NASA GSFC technical representative.

The vendor shall complete the build of the vacuum center at their facility and hold the tool at their facility until the NASA GSFC technical representative inspects the tool prior to shipment to NASA GSFC.

After build of the tool, the vendor shall provide samples of Au thin films on metal coated silicon wafers (substrates to be provided by the technical representative at GSFC shall be both 4” and 8” wafers) deposited in the tool at their facility in order for the NASA GSFC technical representative to witness the successful demonstration of the tool and to give the NASA GSFC technical representative a testable sample that can be evaluated prior to tool acceptance. This sample shall be tested at GSFC for film thickness, uniformity, and electronic properties. The GSFC technical representative will also evaluate a wafer with Au film deposition of about 50nm preceded and followed by an ion clean. Magnetic impurities shall be less than 10 ppm on the surface or in the bulk of the film as measured by SIMS (secondary ion mass spectrometry).

The vendor shall pack and ship the tool to NASA GSFC. The system will be evacuated prior to shipping and shipped under vacuum. Packing shall include wrapping in a clean environment to protect the system from contamination during shipment. Packing shall include a structure for supporting and lifting the tool for transport onto and delivery from the shipping vehicle.

The vendor shall install the tool at NASA GSFC one month after inspection of the tool at the vendor site.

The vendor shall provide for training of NASA GSFC personnel at NASA GSFC and provide all manuals and documentation pertaining to the operation and maintenance of the tool and the subcomponents.

The vendor shall provide and support a warranty of all components on the tool. If the tool has difficulty reproducing the specifications once installed at GSFC, the vendor shall provide support on the tool to establish end user processes that achieve the target specifications of the thin gold films.

Requirements

General

The vendor shall provide a system with all new components. No refurbished equipment will be accepted. No refurbished components or subcomponents will be accepted.

The vendor shall provide an electron beam deposition system meeting or exceeding specifications listed. The vendor shall prove through calculations and performance of past systems that the proposed system shall meet all specifications.

The vendor shall provide a leak tight system (to <1e-9 scale on a helium leak checker), welded on all ports, ferrofluidic feedthroughs, and flanges that are conflat with copper gasket wherever possible.

The interior of the system shall have polished vacuum surfaces.

System and Pumps

The vendor shall provide a vacuum system with roughing pumps and cryopumps sufficient to pump the system to below 5e-8 torr.

The vendor shall provide a roughing pump with sufficient pumping speed that can be located away from the system and still pump the system to the required crossover pressure in a reasonable time (<15 minutes). The roughing pump shall be an oil free pump with at least 36 cfm pumping speed at the mouth of the pump. The preferred pump configuration is one in which the roughing pump is powered off after the roughing of the system is completed to prolong the life of the pump.

The vendor shall provide a cryopump with 10” flange for the chamber that it can reach 5e-8 torr on an overnight (up to 24 hours) pump and maintain good pressure in the tool (2e-7 torr) during deposition after a suitable bakeout. The preferred cryopump shall have a fast regeneration method for when the pump needs to be cycled to room temperature. The cryopump shall be mounted on the chamber to achieve maximum pumping speed but with appropriate protection against metal flakes and particles from getting into the chamber.

The vendor shall provide for automatic regeneration of the cryopump.

The vendor shall provide a gate valve between the cryopump and the chamber that allows for maximum pumping speed of the cryopump to be achieved in the chamber.

Chamber Configuration

The vendor shall provide a vacuum chamber with a throw distance (the distance from the electron-beam source to the substrate) of less than 25 inches

The vendor shall provide a vacuum deposition chamber in which the deposited thin film uniformity is +/-2% across a 100 mm substrate (with allowance of a 0.5 cm exclusion zone at the edge of the wafer.)

The vendor shall describe the motion of the wafer during deposition and mechanisms required to achieve the motion through the plume of evaporated metal which in turn determines the achieved uniformity of the deposited layer. The robustness of the proven design of the deposition method shall be of particular consideration in the assessment of the tool description.

The vendor shall provide a vacuum chamber capable of simultaneous deposition on 8 or more 100 mm (i.e., 4 inch) silicon substrates.

The vendor shall provide a mounting plate and mounting fixtures for the substrates, where non-magnetic, non-ferrous materials are in contact with the wafer surface or nearby the wafer such that, if they are eroded by the ion clean, they do not incorporate magnetic impurities into the film or onto the wafer surface.

The vendor shall provide an electron-beam hearth carousel that accepts four (4) 15-cc crucibles and can rotate in situ, indexing to each crucible location reproducibly.

The vendor shall provide a gate valve matching diameter of the mouth of the cryopump for maximum pumping speed when the cryopump is pumping on the system.

The vendor shall provide all stainless steel, welded gas manifold for argon gas and vent gas (dry nitrogen) into the chamber with VCR fittings. The manifold shall include leak tight shutoff valves and, for the argon, a mass flow controller or automatically controlled needle valve for setting the argon flow to the ion source. Plumbing interior shall be clean and non-contaminating.

The vendor shall provide fixturing for all required water cooling for operation of the tool and its components. This includes any water cooling to the pumps, electron-beam hearth, chamber walls, crystal monitors, ion source, and substrate holder. Water cooling plumbing shall be protected from erosion from ion source and metal fatigue to prevent formation of plumbing leaks.

The vendor shall provide an all-metal shutter for the electron beam hearth with reproducible open/close mechanism for reproducible depositions. The shutter shall be designed to be taken apart and cleaned as needed.

The vendor shall provide pressure gauging for the tool including ion gauges for pressure below 1e-4 torr and thermocouple gauges or equivalent for pressures from atmosphere to 10 millitorr.

Shapers – The vendor shall provide for installation of shapers that can be used to tune the film thickness uniformity. Because these shapers may be in the ion clean, the shaper must be constructed of non-magnetic, non-ferrous material. The vendor shall indicate what thickness uniformity shall be achievable with the shaper option.

Electronics

The vendor shall provide all electronics and power distribution for operation of the electron-beam power supply, pumps, valves, ion source, pressure gauge readout, thickness monitor readout and all other operations of interlocks, computer control, automatic valve control, and other system features provided by the vendor.

Thickness monitors

The vendor shall provide two quartz crystal thickness monitors which can be selected while the chamber is under vacuum. The system shall be used primarily for deposition of uniform thin films of Au and Ti/Au and the system must be able to monitor the thickness for each layer on its own crystal monitor without breaking vacuum. These crystal monitors shall be positioned to provide an accurate calibration of the thickness deposited on all substrates.

The vendor shall provide one other crystal monitor for setting the rate during the depositions prior to opening the shutter. This crystal does not need to meet the accuracy of the dedicated monitors.

All electronics and water cooling shall be provided with the thickness monitors. The crystal monitor shall be programmable and coupled to the electron beam power supply to allow regulation of the deposition rate of each material.

Ion source for wafer cleaning

The vendor shall install an ion source for Argon ion cleaning of the substrates prior to or in between depositions. The ion source shall be able to provide a uniform beam greater than the size of the substrates. The substrates can be rotated over the source to provide uniform cleaning of all substrates. The ion source must be able to clean the deposited molybdenum film without contaminating the film with magnetic impurities (< 10 part per million).

The vendor shall provide a recessed housing for the ion source with a removable lid that protects the ion source from deposition and during chamber maintenance and loading.

The vendor shall provide details on the line of sight of the ion clean to the sample to discuss how the mounting scheme prevents all magnetic contamination from getting milled toward the surface of the wafer during cleaning or any use of the ion source.

The ion source is intended to be used only for wafer cleaning and not during other processes.

Residual Gas Analyzer

The vendor shall provide a residual gas analyzer capable of sensitive monitoring of hydrogen, nitrogen, oxygen, water vapor and other volatiles before, during, and after depositions (up to 60 AMU).

Windows / Spare Ports

The vendor shall provide at least two windows into the chamber for monitoring the electron-beam hearth and the wafer surface. The vendor shall provide mounts for mirrors in the chamber if they are required to observe the hearth and wafer surface.

Windows and other ports shall be protected by a shutter that can be manually operated by the user of the tool at the window.

The vendor shall provide at least 3 spare ports with 2-3/4” conflat for user applications.

Vendor shall supply at least 4 ports at the lower/bottom part of the chamber for future equipment for in-situ wafer control (e.g. temperature measurement of the wafer surface.). These ports shall permit line-of–sight to the wafers.

Shields for walls and shutter

The vendor shall provide removable shields that protect the walls of the chamber. Since these shields may be in line of sight of the ion cleaning source, shields shall be made of or coated with Aluminum, Titanium, or some other low sputter yield, non-ferrous, non-magnetic ion producing material.

The vendor shall provide a non-magnetic shield for the shutter or changeable components for the shutter that can be cleaned while the system continues to be operated.

Automatic Control / Interlocks

The vendor shall provide automatic valve control for pump, vent, and cryopump regeneration. The vendor shall also provide for a maintenance mode wherein the valves can be accessed for servicing.

The vendor shall provide a computer interface for operation of the electron-beam gun. It should readout and log pressure gauges, thickness monitors, and e-beam parameters during a deposition run.

The vendor shall interlock the system so that, for example, the electron-beam gun cannot be operated at high pressure, the roughing valve and gate valve cannot be actuated at the same time, etc.

Spare Parts

The vendor shall provide spare parts for the electron-beam gun assembly.

The vendor shall provide a spare set of shields for the walls of the chamber.

The vendor shall provide a list of consumables such as gaskets and hardware that fit the system

Safety

The vendor shall provide an emergency power off switch that is clearly labeled and accessible to users, posted warnings of high voltage as needed for the electron-beam electronics, and a system the secures all hazards within the system. The system shall be interlocked so that if the hazards are open and accessible, the hazard cannot be actuated (for example, the electron beam power supply cannot be turned on when the skins of the system are open and the area with the high voltage feedthrough is user accessible).

Warranty

The vendor shall provide a twelve month warranty for all parts and labor for the tool and its components and subcomponents

Manuals

The vendor shall provide a full printed set of drawings of the tool, electronic schematics of the tool, and operation of the tool.

The vendor shall provide a parts list and operation and troubleshooting manuals for the components used in the tool.

Upgrades

Spare Planets and Mounting Hardware and Rotational Mechanisms

The vendor shall provide an option for a second and third substrate holder that holds 6” and 8” substrates but does not meet the thickness uniformity.

Shapers for 6” and 8” Substrates

The vendor shall provide an option for shapers that can improve on the thickness uniformity of 6” and 8” wafers for the wafer holder assemblies.

Pump upgrade

The vendor shall provide for an upgrade for a 60 cfm dry roughing pump and upgraded cryopump.

Deliverables of Delivery Schedule

· 1 month from Date of Award (DOA): The vendor shall provide a design for the system that meets the specification outlined in the SOW. The design shall include drawings of the proposed system as well as a parts list of all the components to be included in the system. In addition, the vendor shall provide supporting calculations to show that the technical specifications for temperature and film thickness shall be met.

· 1.5 months from DOA: The vendor shall provide a build schedule and acquired parts list.

· 4.5 months from DOA: The vendor shall provide an interim schedule update report.

· 7.5 months from DOA: Inspection of and testing of tool at vendor site to include production of initial baseline samples.

· 8.5 months from DOA: Installation and acceptance of tool at GSFC. Training of GSFC personnel on the tool.

· 9.5 months from DOA: Completion of training of GSFC personnel on the tool.

Government-Furnished Equipment and Government Furnished Information

NASA GSFC will provide utilities and cleanroom space for installation of the tool per specifications provided by the vendor for electrical power, compressed gases, chilled water, and any other required facilities.

Security

None

Place of Performance

The design and construction of the tool shall take place at the vendor facility. The initial technical inspection of the tool, including operation of the tool to deposit a thin metal layer will be performed at the vendor facility. The tool with be packaged and shipped to NASA GSFC for installation and acceptance. Training of personnel will also take place at NASA GSFC once the tool is installed. The place of acceptance and FOB point of the shipment shall be Destination.

Period of Performance

The period of performance for shall be from DOA through 9.5 months from DOA.