|
All four systems share similar aspects of Zyvex’s core technology for nanomanipulation.
The nProber is the top of the line nanoprobing system specifically designed for
semiconductor characterization. The system is designed for customers working at
small geometries who want to have the most user friendly and efficient system on
the market. The system is semi-automated and has 8 positioners for a variety of
advanced applications.
The dProber is a lower cost solution to a dedicated system. The system has 6
positioners and an XYZ stage for higher throughput but does not have all of the
automation that comes with the nProber. The system replaces the door of a
repurposed SEM at the customer site or can be coupled with a new SEM as the dProber+.
The sProber is a 4 positioner system that includes everything needed for semiconductor
level probing. The system is designed for FA and yield labs that have an SEM being used
for multiple purposes. The sProber is installed quickly by the user when probing is
only needed ‘sometimes.’
The S200 is the most basic system with 4 positioners and targeted for research and
education customers only. The system is meant to be used in a lab with multiple users
and on an imaging platform that is used for many different purposes. The S200 can be
outfitted with multiple upgrades, end effectors and application packages to achieve exactly
what the customer wants.
The sProber, dProber, and nProber are all used extensively for non-visual fault localization.
They can also be used for device characterization, metal-line resistance measurements,
butterfly probing, and bitcell characterization. They can be further upgraded to perform
hot/cold measurements, CV characterization, Pulsing measurements, and Electron Beam Induced/Absorbed
Current characterization. The tools are used at all metal layers and at the contact level to
characterize and find faults.
The Zyvex SEM nanoprober product line is integral in locating non-visual fails. Most commonly,
a failing bit is identified using some larger scale method. The sample is then deprocessed to
contact level (if it hasn’t been already) and put in the Zyvex system. The user probes six
transistors in a reference bit and then six transistors in the failing bit. The data is analyzed
and a problem is found that points to a pair of contacts in a specific transistor. The transistor
is cross sectioned and then put in a TEM. The image of the fail is then used to solve the root
problem. In many cases, customers stop after nanoprobing when the electrical signature
corresponds to previously seen fails. This greatly improves throughput and cycle time. The
system can also be used at higher levels when fails are suspected in the metal levels or when
other tools are unable to resolve a single bit fail. This can keep a user from deprocessing past
a unique fail.
The S200 can be used as an all purpose nanomanipulator platform. The system can be upgraded to
provide for electrical measurements, force characterization, pick-and-place, surface adhesion and
stiction testing, and a numerous types of sample preparation. Some examples include electrical
characterization of a nanolithography built device on a sample, force characterization of a
nanowire, and removal of a specific nanotube for further analysis. The system is perfect for a
lab atmosphere with multiple project ideas.
The system will mount directly on the SEM stage. Depending on the SEM there may be some loss of
tilt, rotation, or Z movement while the head is installed but the majority of the SEM stages will
not be affected by the Zyvex system. With the head removed, full functionality of the SEM is restored.
In most cases, the system can be installed and removed in under five minutes. No system design will
require longer than ten minutes to install or remove.
This varies with the SEM model and the amount of application packages purchased with the Zyvex system.
This can range from one to five ports but the average user will only need two to three open ports.
Zyvex is able to customize all of the flanges and design around different SEM models as well.
The system will replace the entire door and stage of the SEM. The dProber has its own sample stage and
when not probing you can image and move around a sample approximately 25 mm2 in size.
Zyvex nanomanipulators can also work in air and be mounted to optical microscopes. The systems
work well below SEM pressures but contain a few parts that are not UHV compatible. For custom system
requests contact us at sales_ni@dcgsystems.com
All of the Zyvex systems come with a Windows-based software platform to control the manipulators.
The motion itself is controlled by the user through a high-precision joystick. The sProber, dProber,
and nProber all come with integrated software to control the parametric analyzer and Optimizer. This is
an optional upgrade on the S200.
The Optimizer is a downstream ashing tool that uses a plasma outside of the chamber to inject free radical
oxygen into the vacuum system. This free radical oxygen scrubs the chamber of hydrocarbons that lead
to Electron Beam Induced Deposition (a fancy term for contamination). The Optimizer is vital if the user
wants to make ohmic contact with the sample for electrical characterization.
The Optimizer should be run every time the chamber is exposed to air, every time a sample is exchanged,
once in the morning, and once at night. If contamination begins to build up after a long probing session
then the Optimizer should be run as well.
The key difference between these two techniques is how the sample is imaged. SEM based Nanoprobing uses
the SEM as the imaging tool and the probe tips as the contact points. With Atomic Force Probing (AFP) the
sample is imaged using the AFM probe tips which are also used to probe the device. This leads to slower
image acquisition times and possible mechanical damage to the device. The image quality is also affected
by the tip quality and so image quality degrades as the tips are used to probe the devices. As the image
quality degrades it becomes harder to probe and thus more force is needed and the tip quality further
degrades. There is also no real time image for user feedback so the user can not quickly reposition tips
to achieve the best possible contact. Zyvex Instruments prefers the decoupled nature of SEM based Nanoprobing.
Probe Related Questions
Zyvex manufactures and sells the ideal probes for semiconductor and nanoscale science characterization.
Our TP-25 Tungsten NanoSharp Probe Tips have a tip radius of 40nm +/- 10nm with a taper angle of 10º +/- 2 º.
A more detailed datasheet can be found here.
Our probes are general purpose and can be used in almost any application. A few examples include transistor
characterization, metal line characterization, electron beam induced/absorbed current (EBIC/EBAC) measurements,
and nanostructured materials characterization. Contact us if you have any specific application questions at
sales_ni@dcgsystems.com
Probe lifetime can vary widely based on the user’s experience, the sample under study, the application being
performed, the Zyvex system being used, and the environment where the system is installed. Usages can range
from one day of measurements on carbon nanotube electrical characterization to more than three weeks of SRAM
transistor fault localization.
Again this can vary widely depending on the application and user. In general, a semiconductor customer will
use around 1000 probes a year and a university customer will use around 200 probes a year.
Zyvex considers the probes to be consumable items and will not rework or warranty probe tips after they are
used. However, during system training Zyvex will train users on how to use the manipulator to quickly rework
a slightly bent probe tip. This is one of the advantages of using a SEM-based nanomanipulator as your
nanoprobing solution.
These are removable holders that plug into the fine positioner assembly. There are various types of end effectors
that are used depending on the application. The most common end effector holds a single probe.
All of Zyvex’s systems are compatible with industry standard probe tips with a 0.5 mil shank diameter. However,
Zyvex does not guarantee tool performance as specified if third party products are used.
SEM Related Questions
Zyvex has worked with all of the major SEM and SEM/FIB manufacturers to offer systems on the broadest base as
possible. There are systems or designs for almost all of the FEI, Hitachi, JEOL, and Zeiss SEMs and SEM/FIBs.
There are a few conditions that may exempt the tool from probing. The SEM must be turbo pumped for all
electrical applications. A FEG source SEM is required for sub-120nm transistor characterization. If you
have any questions please contact us at sales_ni@dcgsystems.com.
EBID is short for Electron Induced Beam Deposition; sometimes referred to as SEM burn or raster burn. This
effect is seen in all electron beam imaging systems. A user can usually see a dark box on the sample after
imaging the same area for longer than 10 minutes. The presence of this box is sometimes not seen because of
the beam energy or detector used but it is always present. Diffuse hydrocarbons cover the sample, stage, and
chamber walls of the SEM. As the E beam rasters across the sample the hydrogen atoms are knocked off
leaving sp3 hybridized carbon on the sample. This is a diamond-like film that is completely insulating. More
diffuse hydrocarbons move into the area and the process continues. A very thick layer can be built in the time
it takes to probe the device. Zyvex has a tool called the Optimizer to clean the chamber and sample of these
diffuse hydrocarbons before probing and imaging begins. This insures a clean environment for long probing
sessions.
It is widely accepted that high energy E-beams will affect transistor characteristics. Zyvex is constantly
researching this area and working with the SEM manufacturers to stay ahead of the semiconductor community.
Zyvex has a standard procedure to evaluate transistor degradation under a beam of certain energies and sample
currents. Zyvex is currently working well below the threshold needed by the industry today. Because each
chip manufacturer is different, Zyvex normally runs these experiments for customers during the demo of the tool.
For more detailed information please contact us at sales_ni@dcgsystems.com.
Zyvex is constantly working with the SEM manufacturers to source imaging systems with lower and lower beam
energies and sample currents. Zyvex is currently operating the nProber greatly below the threshold needed by
the industry today. For specific beam voltages, currents, and more details please contact us at sales_ni@dcgsystems.com.
Zyvex is constantly working with SEM partners to evaluate and integrate the best suited SEMs available for
the nProber platform. There are multiple platforms in use today and more platforms will be added as materials
change and technologies continue to shrink.
Measurement Related Questions
Yes. The standard procedure utilizes two outer probes as the voltage source and drain. Two inner probes are set
to source zero current and act like high impedance voltage measurement probes. The contact resistance of the
system can then be removed and the true resistance of the nanostructure is measured.
Fortunately, all of the probing done with Zyvex systems is in vacuum and thus there is not a continuous stream
of contamination agents. There are three factors that Zyvex manages to achieve low ohmic contact. First,
Zyvex uses the Optimizer to insure a carbon free environment on the sample. Secondly, Zyvex has a unique in
situ probe cleaning method to insure pure tungsten ohmic contact with the probes. Thirdly, Zyvex has a
recommended procedure to clean the sample prior to probing. Zyvex also has a contact optimization feedback
loop so the user can monitor the quality of the contact in real time.
Nanoprobing is non-destructive to the transistor. However, if the voltage or current levels are applied beyond
the transistor’s normal operating conditions then the transistor can be stressed and possibly damaged. However,
the voltage/current can be set / controlled thru the Zyvex system to ensure that they are well below the range
that would damage the transistor.
There are other techniques like Scanning Capacitance Measurement, Reactive Ion Etching, and Focused Ion Beam
Milling that may weaken devices and result in damage prior to nanoprobing. Since these are not part of SEM
nanoprobing, they should not be used in conjunction with SEM nanoprobing.
All of Zyvex’s systems are outfitted with multiple connection paths to the probe tips. Almost all third party
measurement equipment can be connected to the system. However, Zyvex does not guarantee tool performance as
specified if third party products are used.
Zyvex positioners can handle up to 100V and 200mA. Prober cables can handle up to 200 mA of current and voltages
as high as 250 volts. The probes can take in excess of 4mA and will act like a fuse in the circuit. If a probe
burns out at the point of breakdown during tests, a resistor can be placed in series with the probe. If the
probes touch while they are at high voltage, the instantaneous current can be much higher than 200 mA. In
this situation the sharp probe tips will vaporize similar to a fuse and this will keep such large currents
from damaging any wiring on the device.
back to top
|
© Copyright 2007-2010, Zyvex Instruments. All Rights Reserved. |
|
