EQP - The Mass/Energy Analyzer for Plasma Diagnostics
The EQP high transmission
energy analyser provides ion energy distribution
of plasma ions. The energy distributions
of plasma ions. The ion energy distribution
identifies the energy with which each
species is interacting with the substrate-critical
information; in low damage etch for example.
A 45-degree sector
field energy analyzer is used in preference
to a CMA or Bessell box inline analyzer
for maximum transmission and to provide
minimum perturbation to the ion flight
path within the analyzer for optimum energy
The EQP energy analyzer
provides constant transmission and constant
energy resolution functions throughout
the ion energy range (+/- 100eV, +/-1000eV)
The energy resolution
of the sector field energy analyzer is
better than 0.25eV FWHM.
Energy scanning for
selected ions is automatically controlled
with energy increments selectable from
The EQP system is
floatable to 10KeV using external power
supplies and isolation components.
- A range of laser drilled orifice diameters
from 30µm diameter provides for sampling
of +ve ions, -ve ions, neutrals and radicals.
The office design is optimized for plasma
sampling using pre-thinned material for the
laser drilled component. Each orifice is helium
leak tested to ensure correct conductance.
- Software controlled ion extraction optics
provide for plasma sampling with minimum perturbation
to the plasma.
- A standard connection is included in the
EQP electronics to allow the EQP electronics
to allow the EQP system to be referenced to
an external supply, a plasma electrode for
example. This feature enables ion energy distributions
to be referenced to the substrate’s
- Plasma electrodes coupled to the EQP provide
a substrate during processing. Electrodes
are custom designed to suit RF, DC or pulsed
plasma supplies with heated subtract stages
and water-cooling options available.
- The EQP sampling configuration can be readily
disassembled for ionizer filament replacement
and cleaning, the open design construction
making maintenance a routing in-house procedure.
- The internal EQP ionizer includes two
oxide coated iridium filaments, with a radially
symmetric cage assembled in a close coupled
configuration to the plasma sampling orifice
for high sensitivity analysis of plasma
gas neutrals and radicals.
- EQP software provides for precision control
of the ion source operating parameters including
filament emission, source cage voltage and
the ionizing electron energy.
- A key feature of the EQP ionizer design
is the confinement of electrons within the
cage vicinity ensuring the high degree of
control of the ionizing environment necessary
for the detailed appearance potential measurements
used in the analysis of radicals.
- Electron attachment ionizing option .An
enhancement of the ion source control provides
for analysis of negative ions produced in
the EQP ionizer by electron attachment where
electronegative species are present. This
technique provides valuable information
for the analysis of radical species in electronegative
- A triple filter mass analyser construction
is included in the EQP system. The triple
mass filter has short ‘RF only’
pre and post filters which minimize effects
from fringe fields at the primary mass filter
ion entrance and exit, enhancing peak separation
and transmission particular for high mass
species. This triple filter configuration
has been proven superior in performance
to single filter quadrupoles in recent years.
- Abundance sensitivity is 0.1 ppm. Detection
to 20PPB is available for non-interfering
- The mass filter rods are precision ground
from molybdenum with precision machined
radially supporting ceramics for high-performance,
durability and long stability.
- The mass filter pole diameters of 6mm
and 9mm are offered to suit mass ranges
of: 300,510,1000 & long-term stability.
- The Mass filter pole is powered from
solid-state RF/DC power supplies. A 5-watt
direct coupled compact unit is included
for 6mm pole diameter systems; a 200-watt
remote system is included for 9 mm pole
A pulse ion counting
detector is included as standard offering
seven decades continuous dynamic range.
Counting is via a 24-bit
counter for 1 c/sec resolution throughout
A Faraday cup option extends the range up
to 5 X 1010 c/s for high-density plasma
The EQP software provides
for data acquisition as raw counts, counts
per second, averaged counts over repeated
mass and energy scans significantly increases
signal to notice in the analysis of minor
A TTL output of raw
counts is available via a connector on the
EQP electronics system.
A signal gating input
is included as standard to provide for time
resolved plasma or laser ablation applications,
where energy and mass distributions of selected
species can be analyzed at prescribed intervals
across the plasma afterglow or plasma plume.