IVS 230 CD SEM. Product Catalog For the IVS 230 CD SEM

Transcription

1 IVS 230 CD SEM Product Catalog For the IVS 230 CD SEM

2 IVS 230 Product Catalog Rev 2 March 2000 Copyright 2000 Schlumberger ATE 45 Winthrop Street Concord, Massachusetts (978) Fax: (978) All rights reserved. No part of this publication may be reproduced in any form or by any electronic means, including information storage and retrieval systems, without permission in writing from Schlumberger ATE. Changes are made periodically to the information contained herein. These changes will be incorporated in new editions of this publication. NOTICE: The information contained in this catalog is believed to be accurate and reliable. However, Schlumberger ATE assumes no responsibility for any errors, omissions, or inaccuracies whatsoever. ii IVS 230 Confidential

3 The IVS 230 scanning electron microscope Offering the latest in metrology measurements and automation The IVS 230 SEM provides outstanding measurement precision for CD's and thin film head features and offers a fast, automated wafer loading system and fast pumpdown times. It allows operation at very low voltages for excellent measurements without image "bloom" or electron beam artifacts. Full digital beam control provides superior measurement accuracy and magnification stability. And the IVS 230 is truly "hands-free." No operator assistance is required during job plan execution. With its advanced measurement algorithms, it can measure CD's, contact holes, and thin film head features. It has a pattern recognition success of greater than 90 percent. And it has the smallest footprint of any metrology SEM. The new IVS 230 has been designed with these wide-ranging features to meet the needs of varied customers around the world. TYPES Confidential IVS 230 iii

4 About this catalog The IVS 230 catalog lists the hardware and software features available for the IVS 230 SEM. The purpose of this catalog is to inform you of just what is available on the IVS 230 SEM so you know what you can or cannot offer customers in the way of features and options. Other resources include the User's Guide and Maintenance Manual. Software Release Notes also provide important information on new software features. As release notes are received, they should be placed in this Product Catalog in the appropriate product section. iv IVS 230 Confidential

5 Table of Contents Measurement types... 1 Electron column and detection system... 2 Tool-to-tool matching... 4 Handler configurations... 5 Throughput... 6 Measurement options... 7 Measurement setup features... 8 Pattern recognition Configurations Focusing methods Data/image storage and output System protections, security and controls Vacuum systems System computer controls Options Weights, dimensions and facility requirements...19 Footprint Confidential IVS 230 v

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7 Measurement types The IVS 230 SEM has many built-in algorithms to measure a wide variety of semiconductor and thin film head features. It measures line-space-pitch CD's and contact holes on semiconductor wafers. Special algorithms are also built-in for the thin film head industry to measure top pole and magneto-resistive (MR) features. Semiconductor measurements Measurable CD features are 0.1 to 20 microns with repeatability of <3 nm 3 sigma (or <1%, whichever is greater). Lines, spaces, and line/space pairs can be measured in X and Y direction in a single jobplan. The CD algorithm acquires the image within the measurement gate and does a grey scale profile analysis within the gate to find edges. Gate position and size are freely adjustable. Contact holes (CH) The Contact Hole algorithm provides X- width and Y-width measurements for round features. An ellipse approximation is drawn on the SEM image, connecting the four points found in determining the hole edges. This algorithm works well when holes are vertical. When contact holes do not have sharp vertical edges, the Adaptive Contact algorithm allows you to choose the top or bottom of the hole or a location in between to account for sidewall slope or irregularity. Thin film head measurements Top pole resist frame, MR stripe, MR leads-defining resist, MR leads final, coil resist and finals can be measured in the X direction and the Y direction within a single jobplan. CD measurement repeatability is <10 nm 3 sigma (or <1%, whichever is greater). As with semiconductor measurements, the CD algorithm acquires the image within the measurement gate and does a grey scale profile analysis within the gate to find edges. Gate position and size are freely adjustable during job setup. Runtime image filtering Measurement images can be filtered by 3 x 3, 5 x 5, or 7 x 7 kernels which allow you to manipulate grey scales to make bottoms more visible to the eye. Electronic ruler Manual measurements can be made quickly with on-screen images. Measurement results are output as X and Y distances. Measurement types Confidential IVS 230 1

8 Electron column and detection system The Schottky field emission electron gun allows for precise measurement of semiconductor and thin film head features at low voltages. Electron gun The electron gun is a thermally assisted field emission gun which allows good resolution at low voltages. Beam setpoint selection There are 10 user selectable beam setpoints. A beam setpoint is comprised of accelerating voltage, decelerating voltage, and condenser voltage. The landing energy (accelerating decelerating voltage) can range from 300eV to 2000eV although the most commonly used landing energies are between 500eV and 1000eV. Probe current Probe current range is 5 pa to 100 pa, continuous. Condenser voltage is used to adjust probe current. The Faraday cup is mounted in the stage. Image resolution <3.5 nm at 1 kv 6 nm at 500V Magnification The digital scan control system provides 25 magnification settings ranging from 1500x to 500,000x based on a 150 mm wide viewing image. Magnification is calibrated to a Schlumberger Standards wafer or to a customer preferred reference at the factory. Recalibration is usually not required. Also annual recalibrations are not required. Beam alignment Beam alignment is semi-automated with a wobble function built-in. Alignment is suggested once per shift for each beam setting, but it is possible to go for up to a week between alignments. Beam alignment is carried out using simple menu selections and digital encoder knobs located above the keyboard. Beam alignment knobs are activated only when selected in software. 2 IVS 230 Confidential

9 Stigmation An octapole stigmator is used for beam shape correction. Stigmation adjustments are suggested once per shift for each beam energy setting though it is possible to go up to a week between alignments. Like beam alignment, stigmation adjustments are made using simple menus and digital encoder knobs located above the keyboard. The stigmator knobs are operable only when activated by software. Detector system The Multichannel Plate (MCP) electron detector collects the electrons that form the image. Automatic MCP adjustment on each wafer matches wafer image brightness to images stored in the jobplan. SE (secondary electron) detection is used. The IVS 230 tracks illumination by jobplan and updates illumination based on user-defined limits. Focus system Focus coils in the column shape the beam to provide focus on measurement features. In addition to automatic focus, a manual focus knob controlled by software is provided at the keyboard. For more about focusing, see "Focusing methods" later in this catalog. Electron column and detection system Confidential IVS 230 3

10 Tool-to-tool matching IVS 230 systems can be matched to ensure that jobplans created on one system will run properly on another with the same results. Emergency stop button ON pushbutton (green) lit when on OFF pushbutton (red) lit when off lit when off (red) OFF pushbutton lit when on (green) ON pushbutton stop button Emergency Jobplans Matching systems Systems can be matched to 7.5 nm through a three-step process using the standard error of the Y-estimate. This process can be summarized as follows: Calibrate each system using the same standard wafer or measurement artifact at each of the measurement magnifications. Verify each system's magnification linearity by measuring a single feature across several magnifications (measurement vs. magnification: slope=0). Verify matching of multiple systems (tool A measurement vs. tool B measurement: slope=1.) 4 IVS 230 Confidential

11 Handler Configurations A fast robot wafer handler quickly loads and unloads wafers from the microscope stage. The robot with prealigner removes the wafer from a cassette, aligns it using its notch or flat, and places it on the stage in the orientation you specify. The next wafer is readied for placement on the stage during measurement. Different stage chuck configurations are available. Three cassette platforms Three cassette platforms are standard two for production wafers and one for wafer standards. Each platform can accommodate 100, 125, 150 and 200 mm cassettes without operator adjustment. Robot and prealigner The robot is an R, Z, theta pick-and-place robot with back side only vacuum contact. The prealigner is self-adjusting for mm wafers. Load angle error is ±0.25. Loading failure is <1:10,000 Special wafer protections If a cassette is removed from a platform while one of its wafers is being measured, the system gives a warning and asks you for information on how to return the wafer. It will also prompt you when an unusual event occurs, such as a power failure with wafers on the stage or robot, as to how you wish to proceed in returning the wafers to their proper slots. Stage chuck configurations There are three stage chuck configurations available. Standard configuration Stage accommodates mm SEMI standard wafers without operator adjustment. No hardware change required to mix SEMI standard wafers of any sizes (thin wafers only). Thick round substrates (optional) Stage can be configured for 6-inch round, thick substrates. No hardware change required to mix SEMI standard wafers of any size (thick or thin). Tool-to-tool matching Handler configurations Confidential IVS 230 5

12 Throughput The IVS 230 offers fast wafer throughput for semiconductor wafers and thin film head measurements. Semiconductor throughput Pipelined throughput is >35 wafers/hour (one site per die, five die per wafer). Linked measurement templates provide additional value by allowing more data to be collected per hour than a raw throughput number would indicate. Throughputs as high as 740 measurements per wafer at 4.5 wph have been obtained. With linked templates, multiple measurements can be made from a single acquired image with insignificant impact on wafer throughput. Linked templates also enhance data acquisition rates for thin film head customers. For more about linked templates, see "Measurement setup features." Thin Film Head Throughput Single wafer throughput is > 15 wafers/ hour (one site per die, 16 die per wafer). Pipelined throughput is >15 wafers/hour (one site per die, five die per wafer). 6 IVS 230 Confidential

13 Measurement options The IVS 230 measurement program is called a jobplan. When you set up a jobplan, you make all settings for the sites to be measured. The jobplan is set up on a typical wafer. Then, after checking results and modifying settings (if necessary), you can run the job plan for all of the wafers you want to measure. Jobplans Run your jobplan singly by executing the job in the Execute Jobplan menu. When the jobplan is finished, the system waits until you choose to run another job. The IVS 230 will automatically load a wafer, find and measure the sites you selected, then display and print the results. It then unloads the wafer and continues with another until all wafers in the jobplan are measured. Dynamic queues You can queue up to two job plans while a job plan is running. This way you don't even have to wait until a job is done before getting others ready to run. Use the Queue Dynamic Jobplan menu to queue the jobs without interrupting your jobplan. The jobplan stops running briefly while you queue up the new job or jobs. Queues Put up to 15 jobplans in a queue, then the IVS 230 will run all these jobplans one after the other uninterrupted. Throughput Measurement options Confidential IVS 230 7

14 Measurement setup features The IVS 230 allows wide flexibility in setting up jobplans. One reason for this is the use of templates in setting up jobplans. They make jobplan setup fast and easy. And they also allow you to easily incorporate the same measurement information in other jobplans so you don't always have to start jobplans from scratch. Measurement Gate : X PROFILE Scan MEAS Direction : X 100 I n t e n s i t y 0 X position Templates Jobplan templates allow you to set parameters for a typical site, then you can assign this template to all the sites you want to measure. Jobplan templates speed up job plan setup. They allow a great deal of flexibility since they can be assigned to any site in a jobplan and copied to other jobplans. IVS 230 jobplans give you maximum control over measurements. You can set up easily but you still have many setup options available so your jobplans can be as simple or as complicated as you want. You can measure different types of sites using many templates or you can just measure all the same sites using one template. You can have up to 200 sites in a jobplan. Ten templates per jobplan You can set up to ten unique measurements in a jobplan. You set the measurement parameters for the site in a template, then simply assign that template to as many of the sites you want to measure. For instance, you can have critical dimension (CD) measurements and contact hole or pole measurements in a single jobplan. Just assign the appropriate template to the site you wish to measure. 8 IVS 230 Confidential

15 Linked templates Going one step beyond the concept of templates described on the previous page, linked templates allow you to make different measurements at the same site faster. With linked templates, the system uses a single acquired image to make multiple measurements. Linked templates can greatly increase the amount of essential data collected with an insignificant impact on throughput. Second and subsequent measurements at a site require only 0.2 seconds per measurement. Matrix site setup If your sites are symmetrically located on the die, you can create a site matrix to measure the entire set with a simple setup operation. You can create a matrix of any number of rows and columns, then select only those rows and column you want to measure. For instance, choose sites in every third row and every third column to measure. With proportionally spaced sites, site selection is fast and easy using matrix site setup. Brick Laying By offsetting rows or columns of die, more die can be packed onto a wafer. Using the brick laying function, you can rearrange the wafer map for the offset rows or columns so that it can move to the offset die as easily as to die in the standard matrix pattern. Using brick laying, you can plug in an offset value for any row or column or drive to the offset row or column using the joystick and let the tool calculate the offset for you. A single wafer map may have offset rows or columns but not both. IVS 230 wafer map before brick laying Measurement setup features After brick laying Confidential IVS 230 9

16 Pattern recognition The IVS 230 uses light optical images for global wafer alignment. SEM images are used to more accurately align to the die pattern (die pattern recognition). And pattern recognition near the measurement site (intermediate pattern recognition) ensures that the intended feature is measured. There is also an optional site pattern recognition choice for high mag positioning (75,000X) and contact holes. Filtered grey algorithm The filtered grey algorithm is used on the CD SEM for pattern recognition. It is especially good for low contrast images and thin edges or features where you need to filter out grain or noise. It is also useful if conditions change from site to site. It is designed to detect vertical and horizontal lines only. 2 C Optical global alignment An optical microscope in the wafer chamber allows fast global alignment since it can finish global alignment before pumpdown is complete. The wafer can already be positioned for measurements when pressure is low enough for electron beam operation. There are two selectable optical magnifications, the 150x and 500x. Scan shift Scan shift is a fast, precise way of aligning to the measurement site. First the system moves to the die pattern and finds it. Then the system moves to the site location, but it scan shifts (beam electronically deflected) to find the site pattern. It aligns to the pattern, then scan shifts back so the measurement gate will be aligned to within one pixel of the designated measurement location. With scan shift, stage movements are eliminated and site pattern recognition is fast and precise. The scan shift site pattern recognition feature may be up to 100 microns away from the site in X and Y. 10 IVS 230 Confidential

17 Focusing methods The IVS 230 has both automatic and manual focusing. For automatic focusing, the IVS 230 identifies the focal plane where contrast of the selected feature edge is at a maximum. The manual focus knob is located to the right of the keyboard and can be used for manual tasks. Focus gate Focusing methods To set up for automatic focus during job plan execution, you place a focus gate around a feature edge. The system applies the focus algorithm to this edge, adjusting the focus coils to find maximum edge contrast. The focal length that provides the maximum contrast value is the focus setting. Focusing features Automatic and manual focus. Automatic focus gate is freely adjustable for size and position. Automatic focus uses maximum edge contrast. Manual focus control using digital encoder knob. Focus knob does not function unless activated through software selection. Pat recognition types Focusing methods Confidential IVS

18 Data/image storage and output Measurement data can be output to a printer, to the hard drive, floppy, or to your network. Statistics (mean, max, min, range, sigma, success) can be reported by site, wafer, and lot. Statistics can be shown by type (CD) or by template. Other special data collection and storage features are described below. D# S# Type Mean Max Min Range S(n-1) n 1 1 "CD" "CD" "CD" "CD" "CD" "CD" "CD" "CD" Image storage Images can be stored in a variety of useful formats including TIF, JPG, BMP, and proprietary 16-bit format for off-line measurements. Run Time Image Storage If a measurement error occurs at a site for any reason, you can store the image of this site for later analysis. The system will store the image and an associated data file giving you details about what happened including the error reported and date and time of the measurement error. This allows a closer look at the features in question to determine why the error may have occurred a problem at the site, a problem with job setup, etc. The image can be saved in TIFF or 16-bit format. Printer The printer is a cleanroom compatible Mitsubishi P68U thermal printer for printing images and data. 12 Viewing screen The IVS 230 has a color monitor for viewing images and displaying control and status functions. Pattern recognition and measurement site images are displayed during job execution. Data is displayed during job execution and may be viewed when the job is done. A graphical vacuum status window displays the status of pumps, valves and gauges, shows cassettes being used, and shows wafer location in the wafer chamber. Network connection The IVS 230 is Ethernet compatible through Novel Netware for network storage of data, images and jobplans (network card not provided). Data caching If measurement data is sent to a network instead of storing it on the system, the IVS 230 will automatically create a cache on the system hard drive to store the data if the network is down or the system can't connect for some other reason. This ensures that no data is ever lost. IVS 230 Confidential Throughout Data collection, storage

19 System protections, security and controls The IVS 230 has built-in protections to prevent unauthorized access and to prevent improper operation. System protections Dedicated system controller circuitry protects wafers and the system in the event of a power interruption. System logic rigorously ensures that valves and electronics are not operated in an unsafe manner. Certain actions are not allowed by the system except when carried out in the proper sequence, protecting wafers, pumps, and valves. Security The IVS 230 has the following built-in security systems: User passwords User passwords prevent unauthorized access. Six password levels can be assigned from operator up to service and supervisor. Only the person with supervisor privileges has access to the Password program to make changes. Locked circuit box The main system circuit box is protected by lock and key. Wafer chamber lid The wafer chamber opening mechanism is protected by lock and key. Logic driver board Firmware constantly checks system electronics and vacuum to monitor system functions. It prevents anyone from operating valves in an improper sequence and prevents mishandling of wafers. Software algorithms provide additional protection. Data/image storage System protections Confidential IVS

20 Vacuum systems The vacuum system provides fast, automated pumpdown of the wafer chamber without using a loadlock. Wafer chamber pumping The automated pumping system uses two turbomolecular pumps and two roughing pumps to evacuate the wafer chamber. Wafers are loaded directly into the wafer chamber without the need for a prepumping loadlock. Pumps Pumps used are: Roughing pumps Two dry pumps standard Turbomolecular pumps Two high throughput turbomolecular pumps standard. No maintenance required. Ion pumps There is one ion pump for the electron gun and one for the intermediate section of the electron column. No maintenance required. Cleanliness Class l compatible 0.01 particles added per square centimeter, per wafer pass, measuring particles< 0.3 microns System exterior consists of hinged and removable stainless steel panels 14 IVS 230 Confidential

21 System computer controls The system controller in the IVS 230 provides dependable control with a tape backup and network connections (optional). Colorado Backup-DOS File View Options Utilities Help! Backup Restore Compare Exit Software Main Menu Quick Start Reference BACKUP Click on the Backup button or key <Alt- B> to copy files. RESTORE Click on the Restore button or key <ALT-R) to copy files from tape to any drive destination. COMPARE Click on Compare button or key <Alt-P> to compare files on tape to files on disk. <Alt-Letter> selects menu pulldown <Tab> moves around dialog box Tape drive The IVS 230 is supplied with a tape drive for backup of the system hard drive. It allows fast, dependable backups for the large amounts of files that customers build up on their systems. A Jumbo tape drive supplied with the IVS 230 allows backup of 5 GB per cartridge (compressed). Tape drive software allows you to back up all files or only those files that have not been backed up before (incremental backups) Cartridges can be linked if a backup is ever larger than a single tape's capacity. System controls Industrial computer with Intel Pentium processor. DOS-based user interface and control system. 101-key keyboard for keyboard control and command entry. Joystick for manual stage motion control. Digital encoder knobs for beam alignment and stigmator functions. Vacuum systems System computer controls Confidential IVS

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23 Options This section details the special applications or features available with the IVS 230. These features are optional. They offer additional capabilities for our customers with special needs or requirements. Remote Job Generator Remote Job Generator (RJG) allows you to easily create job plans for new devices of an existing process on a PC, freeing up valuable machine time for production measurements. You just need to create job plans on the tool for one device in the process. Then you can download all these job plans to the Remote Job Generator on your PC. Create new job plans for your next device right on the PC and send them back to the tool. The job plans will be ready to run for the new device. You've created the new job plans without taking the system out of production and with the convenience of creating job plans outside the fab right on your own PC. This allows the job plan to be created before the wafer is available for measurement, significantly reducing work in process hold times. System requirements The Remote Job Generator tools can be run on any desktop computer running Windows NT 4.0 and Internet Explorer 4.0. The tool can be running any version of the system software. Remote Job Generator is capable of reading and writing only job plans that have the center of the die as the die origin. They cannot use a pattern recognition site for the die origin. In order to quickly upload and download job plans from the system, the PC and tool should be connected Remote Job Generator Confidential IVS

24 Options to a network. This is not necessary, however. Job plans can be transferred using floppy disks. RJG CD cells The CD cell is a unique feature of RJG and is not part of the software on the tool. The cell is an array of CD features that are placed around the die. See illustration below. In order to set up a cell, you must know the location of each of the features relative to a cell origin. Then the cell origin can be located anywhere within the die. Based on the cell origin and the offset from the cell origin to each of the features, the system calculates the locations of the features. You assign measurement templates from the existing job plans for each process layer to cell features in RJG. When an RJG-created job plan is run on the system, the selected feature in the cell is measured using the gate placement and focusing method set up in the template. CD cells do not have to be used, but they do provide powerful features. For instance, if you change the location of the cell, the locations of each of the features within the cell are automatically updated. Upper left corner Die CD cell Cell left; shown in street on wafer (right) 18 Confidential IVS 230

25 Specifications Weights, dimensions, and facility requirements Dimensions Measurement module 70 in. (height) x 65 in. (width) x 38 in. (depth) cm (height) x cm (width) x 96.5 cm (depth) Control console 60 in. (height) x 25 in. (width) x 33 in. (depth) cm (height) x 63.5 cm (width) x 83.8 cm Depth with keyboard open: 43 in. (109.2 cm) System footprint Weight With control console wall mounted: 19 sq. ft. (1.7 sq. m.) With control console not wall mounted: 23 sq. ft. 2.1 sq. m.) 2500 lbs (1035 kg); shipping weight approx lbs (1215 kg) Power Ground Air Nitrogen 208V, 50/60 Hz, 40 amp, three phase, computer grade power (NEMA #L21-30 plug) Roughing pumps: two 208V, 50/60 Hz, 20 amp, single-phase circuits (NEMA #L21-20P plug) Meets VDE and BS specifications >90 psi, 3 cfm, hose fitting 1/4 in. o.d., oil free dry filtered down to 3 micron particle size 40 psi, 10 cfm, hose fitting 3/8 in. o.d. Chilled Turbo pumps: 0.6 gpm, 60 F ± 5 F (stable to ±2 F at nominal water value); hose fitting 0.25 in. O.D. x 0.17 in. I. D. Roughing pumps: 0.8 gpm, hose fitting 0.63 in. O.D. x 0.38 in. I.D. 60 PSI nominal value (non DI) water Weights, dimensions Remote Job Generator Vacuum for wafer handler Exhaust -24 to -27 in. HG, 0.8 cfm, hose fitting 1/4 in. o.d. Clean dry air: Atmosphere to -10 in. Hg, 2 cfm, 0.375" O.D. Roughing pumps: Atmosphere, 59 cfm/pump, KF40 fitting Confidential IVS

26 Specifications Temperature 65 to 75 F, ±1 F Range (18 to 24 C, ±0.5 C) Humidity Vibration EMI Acoustic 35 to 80 percent (non-condensing, stable to ±5 percent) Should not exceed 2.0 microns peak-to-peak; 0.7 microns rms Should not exceed 5 mg peak; 1 mg rms Should not exceed 75 dbc Weights and measures 20 IVS 230 Confidential

27 Footprint 2" (5.08 cm) dia. leveling pad 4 places 2" (5.08 cm) dia. caster swivel radius 1" (2.54 cm) 4 places Operator console (71.88) (55.62) (83.82) XX.XX = inches (XX.XX) = centimeters FRONT (48.31) (50.85) (62.53) 1.12 HEX levelling pads 3" (7.62 cm) dia. caster swivel radius.69" (1.75) 4 places Footprint Specifications (78.74) (96.52) (49.86) Measurement module FRONT 3.50 (8.89) (131.45) (165.10) Confidential IVS

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