Clean Room Equipment

Photolithography

Photolithography provides a useful tool for producing structures consisting of micron-sized features. This can be done on a variety of different substrates with relative ease.

GCA AutoStep 200

We are equipped with a GCA Autostep 200 5x reduction step and repeat photolithography system. This tool is capable of exposing features down to 400 nm over a 15 mm square field. Substrates with a diameter of 100 mm can be automatically loaded and aligned. Substrates of 10 mm, 75 mm, 150 mm and 200 mm can be loaded manually. A precise alignment system is included to provide overlay of less than 100 nm. Wafer leveling is used to provide optimum focus range. The focus system uses broadband light and is repeatable to within 0.2µm. Overlay is specified as <0.125µm using local alignment. All tool calibrations are performed automatically, and the focus system uses elaborate compensation for lens heating and barometric shifts.


Control Panel	Inside the GCA AutoStep 200

YES Ovens	YES Vacuum Bake/Vapor Prime and Image Reversal Ovens
We are equipped with two Yield Engineering Systems ovens. The vacuum bake/vapor prime oven provides for pre-programmed dehydration and vapor deposition of a priming agent. The image reversal oven enables clean liftoff pattern transfer using virtually any positive tone photoresist.

Karl Suss MA6 Contact Aligner

The Karl Suss MA6 is a top and bottom side contact lithography printer used for fine line lithography and is capable of sub-micron printing resolution.
Karl Suss MA6 Contact Aligner
	Current setup and features include:
The ability to handle 100 mm diameter wafers. The mask sizes required are either 6- or 7-inch. Future upgrades will enable it to handle 5-inch photoplates. Top side wafer alignment (TSA) using a conventional microscope, wafer and mask stage assemblies. Bottom side alignment (BSA) using bottom viewing optics, CCD imaging with image frame grabber and TV monitor. This allows registration of features on the backside of a wafer to the topside of the same wafer (e.g. through wafer etching, backside window etching for membrane formation, back side masks for wafer-wafer bond alignment, etc.). Automatic computer control with LCD status for User prompting and keypad entry. Up to 100 programs may be stored with five on line at any one time. Each program may be edited for key parameters pertinent to the lithography mode. Fast or slow scanning of mask/substrate with a memory toggle to quickly view between two locations is also available. This makes alignment using one objective easier. 1000 watt mercury arc lamp with "smart power supply" capable of operating in constant power mode, or constant intensity mode. The default is constant intensity mode. In the constant intensity mode, as the lamp deteriorates, the power is automatically adjusted to keep the intensity of the wavelength. Also, the intensity of the lamp may be read from the power supply during exposure or during a lamp test. Choose from five different lithography exposure modes. These include: soft contact, hard contact, vacuum contact, low vacuum contact, and proximity. Each mode is easily selected by keypad and may have certain parameters changed by the User. After successfully completing the training procedures for this tool, the user will be able to perform a full photolithography process for both TSA and BSA using this system.

Reynoldstech Photolithography Hood

This laminar flow hood features a Reynoldstech spincoater capable of handling substrates up to 6" in diameter. Spin speeds can be programmed in from 200-6000 rpm in recipes containing up to 10 steps. A heated tankof n-methyl pyrrolidone is also provided in this hood for stripping resist from wafers. A basin sink is also included.

Reynoldstech Photolithography Hood

Dry Etching

Trion Technologies Oracle

A Trion Technologies Oracle cluster tool with a F₂-based ICP deep RIE chamber and a Cl₂ RIE chamber is used to etch a wider range of materials. This system has two separate chambers connected by a common load lock to alleviate cross contamination concerns. The F₂ ICP chamber uses the same gas mixtures as the Technics RIE and can achieve very high etch rates of the same materials. The Cl₂ chamber runs processes with Cl₂, BCl₃, SF₆ and O₂ gasses and is used primarily for etching Si, GaAs, Al and Cr.

Trion Technologies Oracle

Plasma Deposition

Trion Technologies Orion

Deposited dielectric and semiconductor layers play an important role in the fabrication of micro- and nanostructures. We currently operate a Trion Technologies Orion plasma enhanced chemical vapor deposition (PECVD) system. This tool is capable of depositing uniform layers of SiO₂, low stress Si₃N₄ and amorphous Si at deposition temperatures ranging from room ambient to 600° C.

		Trion Technologies Orion

Physical Vapor Deposition (evaporation)

The deposition of thin films can be performed in a variety of ways. Physical vapor deposition (PVD), also known as evaporation is one of the most commonly used techniques due to its simplicity. Electron beam evaporation offers great flexibility as it allows the deposition of any metal and some alloys and insulating compounds. We currently have two electron beam evaporation systems both equipped with rotary sources that allow for the deposition of up to four materials in a single run. These systems constitute our primary means of depositing metallic thin films but can also be used to put down layers of SiOx and metal-based oxides.

Electron Gun PVD

Metrology Equipment

In order to monitor the progress of samples during fabrication it is necessary to use various types of metrology tools. Our primary means of inspection during the microfabrication process is optical microscopy.

Leitz Ergolux Microscope

Our clean room is equipped with a Leitz Ergolux microscope that is capable of imaging at magnifications up to 2500x. This microscope is also capable of dark field imaging up to 1000x and has an Electro Image Tri-Pix color CCD digital camera for image capture.

	Leitz Ergolux Optical Microscope

Filmetrics F20 and F40		Filmetrics F20 and F40 attached to a Leitz Ergolux Optical Microscope

Thickness and optical constants (n and k) are measured with a Filmeterics F20 Advanced Thin-Film Measurement System. Spectral analysis of reflectance from the top and bottom of the thin film quickly provides thickness, refractive index, and extinction coefficient. Virtually any smooth, translucent, or lightly absorbing film can be measured, including most dielectrics and semiconductors. For measurements on patterned or non-uniform surfaces and other applications that require a spot size as small as 10 microns, we use a Filmetrics F40 Thin-Film Thickness Measuring Tool. The F40 is attached to our microscope and combines spectral reflectance, advanced analysis software, and a c-mount for a CCD camera.

Single layer transparent film stacks can be measured using our Rudolph FTM. This instrument is a noncontact, interferometry based-measurement tool that provides a quick assessment of layer thickness; it is particularly useful for characterizing photoresist.

KLA Tencor Alpha-Step 500 Surface Profiler

	Profilometry is another very useful metrology tool commonly used in micro-and nanofabrication labs. We use a Dektak IIa profilometer in our lab to provide accurate information on the topology of large sample features (>100 nm). Also utilized is the KLA Tencor Alpha-Step 500 Surface Profiler.

KLA Tencor Alpha-Step 500 Surface Profiler

Thin Film Miscellaneous Processing

Strasbaugh 6EC CMP

Chemical mechanical polishing (CMP) is a technique used to planarize surface topography. Our facility includes a Strasbaugh 6EC CMP tool capable of handling whole 3”, 4”, and 6” diameter substrates. This system can be used to planarize silicon and silicon dioxide thin films as well as polymers and other dielectrics and conductors. Surface roughnesses less than 1 nm can be achieved.
		Strasbaugh 6EC CMP

Disco Dad/2H6T Dicing Saw
The dicing saw is used to cut finished substrates into individual die. It can be used with substrates as small as 1 cm² up to 6" in diameter. Substrates must also be less than 1 mm thick. This tool can function in either an automatic or manual mode where single pass cuts can be achieved. All alignment to the substrate is performed by a split field video stereo microscope.
		Disco Dad/2H6T Dicing Saw

Electrical Testing

Signatone Probe Station		Signatone Probe Station
Two manual probe stations are currently available to assist in the electrical testing of samples. Both systems are contained in enclosures that can be optically sealed for photo sensitive measurements. One system features a temperature controlled chuck that can be heated to 300° C without interfering with sensitive electrical measurements. The other is equipped with a high powered optical microscope with a working distance greater than 1 cm. This facilitates probing of submicron structures.

Sample Packaging

K&S Wire Bonders

Aluminum (Al) wedge and Gold (Au) ball bonders are available to assist in sample packaging.

K&S Wire Bonders