semi合集-English.pdf - 第863页
SEMI E115-0302 E © SEMI 2002 9 50.0 60.0 70.0 80.0 90.0 100.0 024 68 1 0 Tune = 3.0 volts Tune = 5.0 volts Tune = 7.0 volts Power Efficiency (%) Load Position (volts) NOTE 1: The Tune Position is at the indicate d fixed …
SEMI E115-0302
E
© SEMI 2002 8
0.0
2.0
4.0
6.0
8.0
10.0
0246810
Real Load Impedance (ohms)
Load Position (volts)
Tune Position Fixed at 5.0 Volts
NOTE 1: For this example, the full-scale voltage for both the Tune and Load Positions is 10 V (i.e., Tune = 5.0 V corresponds to
50% of full scale).
Figure 3
Example Plot of the Real Part of the Load Impedance as a Function of the Load Position Tuning Element in
the Matching Network
-35.0
-30.0
-25.0
-20.0
-15.0
-10.0
0246810
Tune = 3.0 volts
Tune = 5.0 volts
Tune = 7.0 volts
Reactive Load Impedance (ohms)
Load Position (volts)
NOTE 1: The Tune Position is at the indicated fixed value for each set of data. For this example, the full scale voltage for both
the Tune and Load Positions is 10 V (i.e., Tune = 3.0 V corresponds to 30% of full scale).
Figure 4
Example Plot of the Reactive Part of the Load Impedance as a Function of the Load Position Tuning Element
in the Matching Network
SEMI E115-0302
E
© SEMI 2002 9
50.0
60.0
70.0
80.0
90.0
100.0
0246810
Tune = 3.0 volts
Tune = 5.0 volts
Tune = 7.0 volts
Power Efficiency (%)
Load Position (volts)
NOTE 1: The Tune Position is at the indicated fixed value for each set of data. For this example, the full scale voltage for both
the Tune and Load Positions is 10 V (i.e., Tune = 3.0 V corresponds to 30% of full scale).
Figure 5
Example Plot of the Power Efficiency as a Function of the Load Position Tuning Element in the Matching
Network
Table 1 Example Data Table Showing the Matching Network Load Impedance and Power Efficiency as a
Function of the Positions of the Tuning Elements
Load
Position (Volts)
Tune
Position (Volts)
Real Load
(ohms)
Reactive Load
(ohms)
Efficiency (%)
0 3 0.74 -31.75 61.51
1 3 0.91 -31.23 66.36
2 3 1.12 -30.64 70.86
3 3 1.38 -29.96 75.04
4 3 1.72 -29.18 78.88
5 3 2.15 -28.26 82.38
6 3 2.72 -27.17 85.56
7 3 3.50 -25.87 88.39
8 3 4.59 -24.31 90.90
9 3 6.18 -22.42 93.07
10 3 8.57 -20.15 94.91
NOTE 1: For this example, the full-scale voltage for both the Tune and Load Positions is 10 V (i.e., Tune = 3.0 V corresponds to 30% of full
scale). This example only shows data for a fixed Tune position of 3.0 volts. Data is also required at a Tune position of 0.0 V, 1.0 V, etc.
SEMI E115-0302
E
© SEMI 2002 10
RELATED INFORMATION 1
LOAD SIMULATORS
NOTE: This related information is not an official part of SEMI E115 and was derived RF Diagnostic Task Force in
North America. This related information was approved for publication by full letter ballot on November 27, 2001.
R1-1 Types of Load Simulators
R1-1.1 Load Simulators are used to present a known
load impedance to a matching network. One example
of a Load Simulator would be a matching network used
in reverse. This section will describe a Load Simulator
that can be used with typical matching networks that
operate at 13.56 MHz with capacitive load impedances.
These applications include those networks used in
parallel-plate capacitively coupled plasmas and also
those networks used in wafer bias applications, where
the plasma is mostly sustained by another power
source, such as an inductively coupled plasma or a
microwave ECR (electron cyclotron resonance) plasma.
R1-1.2 The typical impedance that is seen by the
matching network depends on the geometry of the
applicator (its capacitance to ground), the type of
plasma (gases), the operating pressure, and the density
of the plasma. Typical impedances seen by the
matching networks operating at 13.56 MHz in
capacitive-loading applications have a real part in the
range of 0.5 to 10 ohms and a reactive part in the range
of –10 to –50 ohms. If a transmission line is used
between the output of the matching network and the
applicator, the impedance will get transformed. The
amount of transformation will depend on the length of
the transmission line, but in general the effect will be to
decrease the real part of the impedance and to decrease
the reactive part of the load (make it less negative). If
the transmission line is long enough, the impedance
seen by the matching network may even look inductive
instead of capacitive because of the impedance
transformation.
R1-2 Load Simulator Design
R1-2.1 A typical design for a Load Simulator operated
at 13.56 MHz uses two capacitors and a 50-ohm load.
A schematic is shown in Figure R1-1. The Load
Simulator consists of a series capacitor, C2, and a shunt
capacitor, C1. The C1 capacitor is in parallel with a 50-
ohm load. The 50-ohm load can be an input port to a
Network Analyzer or a high-power 50-ohm load that
can be used with high-power testing.
R1-2.2 A picture of a Load Simulator of this type of
design is shown in Figure R1-2. Two vacuum variable
capacitors are used, with a copper strap connecting
them. The capacitors shown in the figure are variable
from 8 to 1000 pF. Additional fixed capacitors can be
easily added to the circuit to expand the operating
range. The strap connecting the capacitors adds
roughly 100 nH of inductance to the series part of the
circuit for this example.
R1-2.3 The impedance range for this type of Load
Simulator is fairly broad. A plot of the real part of the
input impedance as a function of the value of the C1
shunt capacitor is shown in Figure R1-3. The real part
of the load varies from close to 50 ohms to around 1.2
ohms at a C1 capacitance of 1500 pF. A plot of the
reactive part of the input impedance is shown in Figure
R1-4. The reactance can be varied as a function of both
the C1 and C2 capacitances. A reactance range of –5 to
–100 ohms is easily achieved for a C2 capacitance
variation of 1500 pF to 100 pF.
R1-3 Measurement of Load Simulator
Impedance and Efficiency
R1-3.1 The impedance and the efficiency of the Load
Simulator can be measured in much the same way as a
matching network. The test setup is shown in Figure R-
5. A special fixture may be required to adapt the input
connection of the Load Simulator to a coaxial
connector.
R1-3.2 Calibrate the Network Analyzer at the desired
operating frequency (e.g., 13.56 MHz). The Network
Analyzer shall be calibrated for measuring the
reflection coefficient at test Port 1 and for measuring
the transmission coefficient at test Port 2 (see Figure R-
1) using the calibration kit provided with the Network
Analyzer. This measurement requires measuring the
S11 and S21 S-parameters and requires a full 2-port
calibration. The calibration shall be performed at fixed
frequency (continuous-wave operation) using the
lowest bandwidth possible (typically 10 Hz). The
calibration for each port shall include the additional test
cables and any additional adapters.
R1-3.3 After calibration of the Network Analyzer, the
cable connected to Port 1 of the Network Analyzer shall
be connected to the input of the Load Simulator. The
cable connected to Port 2 of the Network Analyzer shall
be connected to the output of the Load Simulator.
R1-3.4 The tuning elements (variable capacitors) shall
be moved to their minimum positions before the
measurement is initiated. After all connections are
visually inspected for proper contact and the Network
Analyzer has stabilized, the value of the input