1. Technical Field
The present invention relates generally to industrial power delivery
systems and, more particularly, to an industrial power delivery system having a
modular architecture with digital communications links interconnecting the modules.
Conventional power delivery systems are typically serviced by power
supplies which are specifically designed for that particular application. These
power supplies, however, lack modularity and flexibility for expansion in order
to facilitate design and manufacture. Further, such power supplies do not typically
include fault tolerant communications between modules. Further yet, such power
supplies have limited redundancy and power handling capability.
With reference to a specific application, material processing such
as plasma deposition and sputtering through the utilization of plasmas has been
known for many years. These processes require power delivery systems. Such processes
generally require generation of either a radio frequency (RF) or high voltage direct
current (DC) power signal coupled to a plasma chamber. Generating a power signal
generally entails chopping and rectifying relatively high voltages, such as 270
Volts DC. The chopping and rectifying process generates spurious electric and magnetic
fields that couple into nearby circuitry resulting in a relatively high electrical
noise environment. The spurious fields that couple into data circuitry may cause
a degradation in signal quality leading to possible data corruption. High-speed
data communication lines are particularly susceptible to signal degradation and
data corruption due to the relatively low noise signal amplitudes required for
high speed communications.
Thus, it is desirable to provide a power supply which enables design
flexibility and scalability for an industrial power delivery system and provides
data communications unaffected by the power supply environment.
SUMMARY OF THE INVENTION
This invention is directed to a power generator system including
a power module for receiving an electrical energy input and generating an electrical
energy output, the power module includes a digital control input. A sensor module
monitors the output of the power module. The sensor module includes a digital sensor
output and generates a digital sensor signal on the digital sensor output that
varies in accordance with the electrical energy output. A control module has a
digital measurement input for receiving the sensor signal. The control module determines
parameters that vary in accordance with the electrical energy output. The control
module includes a digital control output connected to the digital control input.
The control module generates a control signal applied to the digital control input
for controlling the power module.
This invention is also directed to a power delivery system that receives
an input power and generates an output power to a load. The power delivery system
includes a power generator which receives the input power and generates the output
power. The power generator includes a first digital interface. An impedance matching
network is interposed between the power generator and the load. The impedance match
network including a second digital interface. An output sensor is disposed in proximity
to the load and senses a parameter associated with the power generator output.
The output sensor includes a third digital interface and generates a digital sensor
signal via the third digital interface that varies in accordance with the sensed
parameter. A controller receives the sensor signal and determines a control signal
for output to the power generator. The controller includes a fourth digital interface
and generates the control signal via the fourth digital interface for communications
with the first digital interface. The power generator varies the output power in
accordance with the control signal.
For a more complete understanding of the invention, its objects and
advantages, reference should be made to the following specification and to the
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings, which form an integral part of the specification, are
to be read in conjunction therewith, and like reference numerals are employed to
designate identical components in the various views:
DETAILED DESCRIPTION OF THE INVENTION
- Fig. 1 depicts a block diagram of a plasma chamber control system having a
power delivery system arranged in accordance with the principals of the present
- Fig. 2 is a block diagram of a power delivery system of Fig. 1 arranged in
accordance with the principles of the present invention;
- Fig. 3 is a block diagram of the power generator of Fig. 2;
- Fig. 4 is a block diagram of an alternate arrangement of the power generator
of Fig. 2;
- Fig. 5 is a star network configuration for linking the modules of the present
- Fig. 6 is a more generalized star network configuration for linking the modules
of the present invention; and
- Fig. 7 is a bus network configuration for interconnecting the modules arranged
in accordance with the principals of the present invention.
Fig. 1 depicts a plasma control system 10 arranged in accordance
with the principles of the present invention for controlling a plasma chamber 12.
Plasma control system 10 includes a plasma chamber 12, such as may be used for
fabricating integrated circuits. Plasma chamber 12 includes one or a plurality
of gas inlets 14 and one or a plurality of gas outlets 16. Gas inlet 14 and gas
outlet 16 enable the introduction and evacuation of gas from the interior of plasma
chamber 12. The temperature within plasma chamber 12 may be controlled through
a heat control signal 18 applied to plasma chamber 12.
A plasma controller 20 receives inputs from the plasma chamber 12.
These inputs include a vacuum signal 22 which indicates the level of vacuum in
plasma chamber 12, a voltage signal 24, and a signal 26 indicating the ratio of
flows between the inlet and the outlet gases. As one skilled in the art will recognize,
other inputs/outputs may be received/generated by plasma controller 20. Plasma
controller 20 determines a desired input power to be applied to plasma chamber
12 through a power delivery system 28, as will be described in greater detail herein.
Power delivery system 28 outputs a predetermined electrical signal at a predetermined
frequency and power rating. The voltage output from power delivery system 28 is
applied to plasma chamber 12 in order supply sufficient energy to operate plasma
Fig. 2 depicts a block diagram of power delivery system 28. Power
delivery system 28 includes a delivery system 30 which includes a power generator
or power generator module 32. Power generator 32 receives an input signal, such
as an alternating current (AC) input signal from AC input/main housekeeping module
34. Power is received by AC input 34 through an AC receptacle 36. AC input 34 conditions
the AC signal for application and input to power generator 32. Power generator
32 is embodied as any device which converts an input signal to a predetermined
output signal. AC input 34 also converts the AC input signal to a low level direct
current (DC) signal for powering logic level components.
Preferably, power generator 32 is configured to output a radio frequency
(RF) signal by converting the AC input to a predetermined DC voltage. A pair of
switches, such as a push pull amplifier configuration, in turn converts the DC
voltage to an RF output voltage which may be filtered prior to output from power
generator 32. The operation of power generator 32 may be any type of conventional
operation known in the art, including single and two stage conversions.
Of particular interest to the subject invention is the interconnection
between the modules of power delivery system 28 and power generator 32, as will
be described herein. Power generator 32 generates an output voltage to an impedance
match network or module 38 prior to application to a load 40. Impedance match module
38 typically provides a variable impedance between power generator 32 and load
40 in order to maintain a predetermined impedance at the output of power generator
32, typically 50 ohms.
An output metrology module or output sensor 42 receives the power
output from impedance match network 38 prior to application to load 40. Output
sensor 42 measures predetermined parameters found in the output from impedance
match network 38. For example, output sensor 42 may measure one or a plurality
of parameters including voltage, current, power, frequency, phase, or other parameters
of interest in generating a power output to load 40.
Both impedance match network 38 and output sensor 42 generate data
signals to delivery system controller 44. Delivery system controller 44 receives
data signals from one or both impedance match network 38 and output sensor 42.
Delivery system controller 44 receives the data and generates at least one of a
control or data signal to power generator 32, as will be described in greater detail
herein. Delivery system controller 44 may also generate control signals to or exchange
data with each of match network 38 and output sensor 42.
Delivery system controller 44 also exchanges data and control signals
with an input/output (I/O) adapter or adapter module 46, also known as a peripheral
optional device (POD). I/O adapter 46 enables communications with external devices,
such as an overall system controller, plasma system controller, test module, user
input module, or other modules which may desire to share data with or control operation
of delivery system 30. Delivery system controller 44 also exchanges data and control
signals with AC input 34 to enable control of AC input 34.
A particular feature of the subject invention is directed to communications
between various modules of power delivery system 28. More specifically, delivery
system controller 44 functions as a common controller core which interconnects
system and subsystem modules via high speed, digital communications links 33, 35,
39, 43, and 47. These communications links enable single or bidirectional communications
for data and control signals as design criteria dictates. Communications link 33
interconnects power delivery system 44 with delivery system controller 44 to enable
high speed, bidirectional communications. Communications link 39 interconnects
impedance match network 38 with delivery system controller 44 as required. Communications
link 35 interconnects AC input 34 with delivery system controller 44. Communications
link 43 interconnects output sensor 42 with delivery system controller 44 as required.
Communications link 47 interconnects I/O adapter 46 with delivery system controller
As will be described herein, such a configuration enables systems
with different features to be assembled independently of the technologies utilized
in the modules. Accordingly, power delivery system designs of varying scope and
complexity may be developed more quickly and more reliably.
Delivery system controller 44 communicates with each of power generator
32, impedance match network 38, output sensor 42, AC input 34, and I/O adapter
46 using a digital communications protocol, which preferably is a high speed digital
communications protocol. The protocol may include error detection and correction
to improve reliability of communications between system controller 44 and each
device with which power controller 44 exchanges data. Such a protocol enables control
and feedback signals to have a very high dynamic range compared to traditional
analog methods for control and measurement. To effect the digital communications,
each module described herein may have a digital communications port, and each communications
link functions cooperatively to define a digital interface between the connected
modules to exchange data and control signals.
More specifically, power delivery system 44 communicates with the
modules in a technology-independent manner across the communications links 33,
35, 39, 43, and 47 so that data may be encoded for communications between, for
example, power delivery system controller 44 and impedance match network 38, output
sensor 42, AC input 34, and I/O adapter 46. That is, data is exchanged using a
protocol rather than traditional analog voltages, which can be sensitive to noise.
The data communications between the respective modules transfer values rather than
signal levels indicative of a value. For example, if output sensor 42 measures
one or all of voltage, current, or power, output sensor 42 outputs a digital signal
to indicate respective volts, amperes, or watts. In such a configuration, the modules
operate independently of methods used for determining these quantities. The modules
simply determine the value of the quantity of interest. As an added benefit, the
modules are redesigned, the redesigned modules may be substituted so long as they
use the predetermined communications protocol.
In the block diagram of Fig. 3, power generator 32 includes one or
a plurality of modules interconnected using digital communication links 49a, 49b,
49c, 55, 51, and 61, which operate similarly to those described with respect to
power delivery system 28 of Fig. 2. Power generator 32 is particularly directed
to flexibility in providing power modules so that the power output of power generator
32 may be scaled in accordance with the particular design requirements. Power generator
32 includes a plurality of power modules 48a, 48b, 48c. Power modules 48 receive
an input power from AC input/main housekeeping module 50, which operates as described
above with respect to Fig. 2, and generates an output power. The output power is
applied to combiner module 52.
Combiner module 52 receives the respective outputs from power module
48a, 48b, and 48c and combines the outputs for application to sensor module 54.
Sensor module 54 may operate similarly as described with respect to output sensor
42 of Fig. 2. More particularly, sensor module 54 may monitor particular parameters
of the output power generated by power generator 32. That is, sensor module 54
senses parameters in the output power generated by power generator 32 prior to
application to impedance match network 38 of Fig. 2. On the other hand, output
sensor 42 measures predetermined parameters prior to application of the output
power to load 40.
Power generator 32 also includes a control module 57 including common
controller core 56. Common controller core 56 operates as a local controller for
power generator 32. Common controller core 56 is interconnected to an excitation/metrology
module 58, which also forms part of control module 57. Control module 57 exchanges
data and control commands with a predetermined, variable number of power modules
48, such as power modules 48a, 48b, 48c, sensor module 54, and AC input 50 via
digital communications links 49a, 49b, 49c, 55, and 51. The number of power modules
varies in accordance with the desired output of power generator 32. Control module
57 also exchanges data and control commands with I/O adapter 60 via digital communications
Excitation/metrology module 58 receives data from sensor module 54
and general parameters of operation from common controller 56. Control module 57
and its components then generates control commands to operate each of respective
power modules 48a, 48b, 48c in order to vary the power output from each power module
48a, 48b, 48c, prior to application to combiner module 52. Data may be exchanged
between each of these modules as described above with respect to Fig. 2. In particular,
excitation/metrology module 58 exchanges data with each of power modules 48a, 48b,
48c, sensor module 54, AC input 50, and I/O adapter 60 utilizing digital communications
implementing any of a number of predetermined communications protocols.
Fig. 4 depicts a block diagram of an alternative embodiment of power
generator 32. The power generator 32 of Fig. 4 is similar to power generator 32
of Fig. 3 with the exception that power modules 48a, 48b, 48c do not all feed combiner
module 52, as will be described in greater detail herein. Because of similarities
between Figs. 3 and 4, like reference numerals from Fig. 3 will be used to refer
to like elements in Fig. 4.
The components of Fig. 4 operate similarly as described in Fig. 3
with the exception that the outputs from each respective power module 48a, 48b,
48c, are combined to generate a pair of power outputs power output 1 and power
output 2. Power module 1 48a provides an output to sensor module 54' which then
provides power output 1. As described above, sensor module 54' may monitor particular
perimeters of the output power generated by power module 1 48a. Similarly to Fig.
3, power module 2 48b and power module 3 48c provide respective outputs which are
applied to combiner module 52. Combiner module 52 receives the respective outputs
from power modules 48b and 48c and combines the outputs for application to sensor
module 54". Sensor module 54" senses parameters in the output power generated by
power generator 32 prior to application to impedance match network 38 of Fig. 2.
Sensor module 54" provides an output signal on communications link 59 to excitation/metrology
module 58, which operates as described above.
The configuration of Fig. 4 provides flexibility, such as may be
required when power generator 32 must generate dual frequency outputs. In this
manner, power module 48a may output a first frequency, and power modules 48b and
48c may output a second frequency. As shown in Fig. 3, power modules 48b and 48c
are combined by combiner module to provide a higher power output at the second
Power generators 32 of Figs. 3 and 4 may operate in conjunction with
power delivery system 28 of Fig. 2. Alternatively, power generators 32 may operate
independently and outside of a power delivery system to implement a less complex
system. In such a configuration, power generators 32 may also include an I/O input/output
adapter module 60 to enable communication with other devices as described above
with respect to Fig. 2.
As discussed above, the modules described with respect to Figs. 2
and 3 may be interconnected and exchanged using a digital communications format.
Interconnection of the modules may be achieved using direct or network communications.
Examples of network communications of the modules may be seen with respect to Figs.
5 through 7. In particular, Fig. 5 depicts a star network 66 having a plurality
of modules M1 68, M2 70, M3 72, M4 74, and M5 76. A plurality of communications
links interconnect each module with network controller or connector NC 78. For
example, communications link 80 interconnects module M1 68 with network controller
NC 78. Communications link 82 interconnects module M2 70 with network controller
NC 78. Communications link 84 interconnects module M3 72 with network controller
NC 78. Communications link 86 interconnects module M4 74 with network controller
NC 78. Communications link 88 interconnects module M5 76 with network controller
NC 78. Star network 66 enables each respective module M1 through M5 to communication
directly with each of another respective module through network controller NC 78.
Fig. 5 depicts a network 90 having a plurality of modules M1 92,
M2 94, M3 94, M3 96, M4 98, and M5 100. The modules of network 90 communicate directly
and without the need for a network controller, as each module operates as a network
controller. For example, communications link 104 interconnects module M1 92 with
module M2 94. Communications link 106 interconnects module M1 92 with module M3
96. Communications link 108 interconnects module M1 92 with module M4 98. Communications
link 110 interconnects module M1 92 with module M5 100. Communications link 114
interconnects module M2 94 with module M3 96. Communications link 116 interconnect
module M2 94 with module M4 98. Communication link 118 interconnects module M2
94 with module M5 100. Communications link 122 interconnects module M3 96 with
module M4 98. Communications link 124 interconnects module M3 96 with module M5
100. Communications link 126 interconnects module M4 98 with module M5 100.
Network 90 enables each respective module M1 through M5 to communication
directly with each of another respective module. Each module M1 through M5 inherently
functions as a network controller to select the best path between any two modules.
Communications need not occur directly module to module and may occur through modules.
For example, module M1 92 may communication directly with module M4 98 through
communications link 108. Alternatively, module M1 92 may communication with module
M4 98 by first communicating with M2 94 through communications link 104. Module
M2 94 may then communicate with module M4 98 through communications link 116. In
the configuration of Fig. 6, each module operates as if in an internet-type configuration.
Fig. 7 depicts an alternate network configuration. In particular,
Fig. 6 depicts a bus network 130 having modules M1 132, M2 134, and M3 136. The
modules M1 132, M2 134, and M3 136 communicate via a bus 138. Accordingly, each
module M1 132, M2 134, and M3 136 is addressable so that data may be exchanged
via bus 138 using any of a number of bus addressing schemes. A plurality of communications
links interconnect the modules to bus 138. In particular, communications link 140
interconnects module M1 132 to bus 138. Communications link 142 interconnects module
M2 134 with bus 138. Communications link 144 interconnects module M3 136 with
The communication links described above are implemented utilizing
single or multi-layer protocols, many of which are known in the art. Utilizing
a multi-layer protocol enables substitution of modules and scalability of modules
so long as each substituted or added module utilizes the particular layered protocol.
Further, the communications links may be implemented using a number of known formats
including low voltage differential (LVD), fiber optic cables, infrared transceivers,
and wireless, radio communication techniques. Further yet, as discussed above,
power generator 32 may be incorporated within power delivery system 28 or may operate
independently of power delivery system 28.
Accordingly, the invention described herein provides a modular architecture
for an industrial power delivery system which is both modular and scaleable. The
power delivery system enables different features to be assembled independently
of the technologies used in the modules. Accordingly, power delivery products with
expanded or reduced capabilities can be produced much more quickly.
While the invention has been described in its presently preferred
form, it is to be understood that there are numerous applications and implementations
for the present invention. Accordingly, the invention is capable of modification
and changes without departing from the spirit of the invention as set forth in
the appended claims.