semi合集-English.pdf - 第837页

output encoder v alue that corresponds to the position of a variable tuning element in a Matching Network. For example, the voltage from a rotary potentiometer on the rotating shaft of a variable capacitor (t he “Tuning …

4 Referenced Standards

4.1 SEMI Standards

SEMI E10 — Specification for Definition and

Measurement of Equipment Reliability, Availability,

and Maintainability (RAM)

SEMI E78 — Electrostatic Compatibility - Guide to

Assess and Control Electrostatic Discharge (ESD) and

Electrostatic Attraction (ESA) for Equipment

SEMI E114 — Test Method for RF Cable Assemblies

Used in Semiconductor Processing Equipment RF

Power Delivery Systems

SEMI E115 — Test Method for Determining the Load

Impedance and Efficiency of Matching Networks Used

in Semiconductor Processing Equipment RF Power

Delivery Systems

SEMI E135 — Test Method for RF Generators to

Determine Transient Response for RF Power Delivery

Systems used in Semiconductor Processing Equipment

4.2 IEEE Standard

IEEE-STD-383 — IEEE Standard for Type Test of

Class 1E Electrical Cables, Field Splices, and

Connections for Nuclear Power Generating Stations

4.3 MIL-Specification

MIL-C-17G — General Specification for Cables, Radio

Frequency, Flexible and Semirigid

MIL-PRF-39012D — General Specification for

Connectors, Coaxial, Radio Frequency

NOTICE: Unless otherwise indicated, all documents

cited shall be the latest published versions.

5 Terminology

5.1 Abbreviations and Acronyms

5.1.1 CVD — Chemical Vapor Deposition

5.1.2 PVD — Physical Vapor Deposition

5.1.3 VSWR — Voltage Standing Wave Ratio

5.2 Definitions

5.2.1 cable assembly — the section of cable

(transmission line), including the connectors, used to

connect various parts of the RF power delivery system.

1 Institute of Electrical and Electronics Engineers, IEEE Operations

Center, 445 Hoes Lane, P.O. Box 1331, Piscataway, New Jersey

08855-1331, USA. Telephone: 732.981.0060; Fax: 732.981.1721

website: www.ieee.org

2 Available from Naval Publication and Forms Center, 5801 Tabor

Avenue, Philadelphia PA 19120 U.S.A website:

www.dodssp.daps.mil/products.htm.

5.2.2 electrical length — the length of the cable

assembly at the operating frequency expressed in terms

of degrees, where one wavelength at the nominal

operating frequency is equal to 360°.

5.2.3 harmonic frequency — the harmonic frequencies

are defined as integer multiples of the fundamental

frequency. For example, the second harmonic of 13.56

MHz is 27.12 MHz.

5.2.4 load Q — the quality factor, Q, of the load is

defined here as the magnitude of the reactive part of the

load divided by the real part of the load. For example, a

load impedance of 2 – j20 ohms would have a load Q of

10.

5.2.5 matched load — a matched load impedance is

defined as typically having a magnitude of 50  3.3

ohms at a phase angle of up to  3.8°. In other words,

the load is considered matched if the reflection

coefficient is no greater than 0.032 at any phase angle.

5.2.6 matching network — the device used to

transform the impedance of the load (chamber/chuck)

to match the impedance of the generator/cable

assembly, which is typically 50 ohms.

5.2.7 matching network load impedance — the

impedance of the load to which the matching network is

matched.

5.2.8 MTBF

— mean (productive) time between

failures; the average time the equipment performed its

intended function between failures; productive time

divided by the number of failures during that time.

Only productive time is included in this calculation.

5.2.9 power efficiency — the power efficiency of a

matching network is defined as the power exiting the

network (output power) divided by the power entering

the network (input power).

5.2.10 RF applicator/interface — the part of the

chamber where the RF system is terminated. This

interface can either be a chuck (driven electrode) or the

coil/antenna part of a plasma source.

5.2.11 RF system — the RF system is defined as the

combination of the generator, matching network,

chamber interface, and the associated connecting cable

assemblies that are specific to a particular tool/chamber.

5.2.12 tap point — for some systems, partial tuning of

the matching network is achieved by switching in a

combination of fixed tuning elements, such as different

values of capacitors. The tap point is defined as the

position of the switch(es) that connect or disconnect

tuning elements in the matching network circuit.

5.2.13 tuning element position — the position of the

tuning element is defined as the output voltage or

SEMI E113-1104 © SEMI 2001, 2004 2

output encoder value that corresponds to the position of

a variable tuning element in a Matching Network. For

example, the voltage from a rotary potentiometer on the

rotating shaft of a variable capacitor (the “Tuning

Element”) would be referred to as the capacitor’s

“Position”. In this example, the position/voltage

corresponds to a certain shaft location or position.

6 Ordering Information

6.1 Semiconductor manufacturers may use this

standard when procuring processing equipment to

specify RF power delivery system performance and

documentation. The equipment suppliers may also use

this document to specify the RF system components

and subassemblies.

6.2 Orders for equipment in accordance with this

standard shall include:

6.2.1 This specification number and date of issue.

6.2.2 Any certification showing passage of

qualification tests required to be provided (optional).

6.2.3 Any test results required to be included in reports

to be provided (optional).

7 Requirements

7.1 Semiconductor processing equipment shall be

designed and built with a reliable RF power delivery

system. The requirements defined in this specification

address the integrated RF system as well as the

following RF power delivery system components: the

RF cable assemblies, the matching network, the

generator, and the RF applicator/interface, as well as

specific components of these assemblies or systems.

7.2 The mean (productive) time between failures

(MTBF

), as outlined in SEMI E10, of the generator,

matching network, and the RF power delivery system

as a whole shall be provided by the supplier, as well as

the test method used to determine MTBF

7.3 RF Cable Assemblies (Transmission Lines)

7.3.1 Many RF power delivery systems use RF cable

assemblies to transfer power from the generator to the

input of the matching network and, in some cases, from

the output of the matching network to the process

chamber (e.g., the chuck assembly). All cable

assemblies shall adhere to industry standards for cables

and connectors (e.g., MIL-C-17G, MIL-PRF-39012D,

IEEE-STD-383) in terms of rated power/voltage/

current, allowed bending radius, expected variation in

characteristic impedance, and attenuation at the

expected operating frequency(s) for the specific cable

type (e.g., RG-217, RG-218) per the cable

manufacturer’s specifications. SEMI E114 or an

equivalent test method(s) shall be used to determine the

electrical length, power dissipation (loss), and

characteristic impedance of the RF cable assemblies.

7.3.2 The length of the cable assemblies used to

connect portions of the RF power delivery system shall

be specified in terms of electrical length at the nominal

operating frequency, in addition to the nominal physical

length. The electrical length shall be given in terms of

degrees of phase shift. Variations in the dielectric

properties (e.g., phase velocity, characteristic

impedance) of the cable assemblies can cause the

electrical length to differ between assemblies.

7.3.3 The electrical length of cables used between the

matching network and the chamber (if any) shall be

specified to within 0.25° of the standard electrical

length value at the operating frequency for fixed

frequency systems or at the midpoint frequency for

variable frequency systems, for frequencies less than or

equal to 13.56 MHz. For frequencies above 13.56

MHz, the length should be specified to a value (in

degrees) equal to the frequency in MHz multiplied by

0.018 (e.g., the specification for 60 MHz would be

60  0.018 = 1.1°). For example, at 13.56 MHz, the

physical length of typical cable (RG-217)

corresponding to 0.25° of phase shift (0.5° of reflection

coefficient phase shift) would be approximately 1 cm.

This specification would result in impedance variations

seen by the matching network of less than

approximately 1 percent between processing chambers.

7.3.4 The length of cables used between the matching

network and the generator shall be specified to within

1.0° of the standard electrical length value at the

operating frequency for fixed frequency systems or at

the midpoint frequency for variable frequency systems,

for frequencies less than or equal to 13.56 MHz. For

frequencies above 13.56 MHz, the length shall be

specified to a value (in degrees) equal to the frequency

in MHz multiplied by 0.074 (e.g., the specification for

60 MHz would be 60  0.074 = 4.44°). For example, at

13.56 MHz, the physical length of typical cable (RG-

217) corresponding to 1.0° of phase shift (2.0° of

reflection coefficient phase shift) would be

approximately 4 cm. This specification would

minimize the impedance transformation at the harmonic

frequencies (10° of phase shift at the 10

harmonic

frequency).

7.3.5 The expected power dissipation in the cable

assembly(s) supplied with the system shall be provided

as a function of the operating frequency(s) of the

system. The amount of power transmitted through the

cable assembly shall be given in terms of dB (decibels)

and percentage. The relationship between dB and

percentage is given as:

SEMI E113-1104 © SEMI 2001, 2004 3

Percentage = 100  10

(dB/10)

For example, approximately 94.8% (–0.232 dB of loss)

of the power at 13.56 MHz will be transmitted through

a cable assembly made from RG-217 cable with a

physical length of 15.24 meters (electrical length of

375.74°). In other words, 5.2% of the power is

dissipated in the cable assembly at 13.56 MHz.

7.4 Matching Networks

7.4.1 Matching networks transform the impedance of

the plasma load to match the impedance of the

generator, which is nominally 50 ohms. The

transformation is achieved by the use of various

reactive components, such as capacitors and inductors,

that “tune” the matching network by transforming the

impedance at the output of the network to the input of

the matching network. For a given frequency, there is a

fixed relationship between the impedance at the input of

the matching network and the impedance at the output

of the matching network (the load impedance). In other

words, the impedance to which the matching network is

matched (the load impedance) can be determined if the

transform properties of the network are known for a

given frequency. Typically, there are two methods of

impedance transformation. The first method uses a

fixed frequency (e.g., 13.56 MHz) and variable tuning

elements, while the second method uses a variable

frequency and fixed tuning elements. Specifications for

both methods are given below. SEMI E115 or an

equivalent test method(s) shall be used to determine the

load impedance and efficiency of matching networks

that are designed to operate at fixed frequency with a

50-ohm input impedance.

7.4.2 For those systems that use fixed frequency

operation, matching networks typically have two

variable tuning elements, which are usually variable

capacitors and/or inductors. These variable tuning

elements typically have an output voltage or encoder

value that corresponds to a certain value of the element

(i.e., an output voltage will correspond to a specific

value of capacitance or inductance in the matching

network). The value of the output voltage or encoder

value is referred to as the tuning element position. To

obtain information on the operation and performance of

the matching network, the tuning element positions

must be provided as outputs.

7.4.3 For those systems that use variable frequency

operation, matching networks typically have fixed

tuning elements (no variation) or tap points between

fixed tuning elements, and the frequency is varied to

obtain the best matched condition. In some cases, the

tap points are also varied for matching. To obtain

information on the operation and performance of these

types of networks, the operating frequency and the

input impedance (or reflection coefficient magnitude

and phase angle) shall be provided. For those systems

that have variable tap points, the tap point position shall

also be provided as an output.

7.4.4 For matching networks run at a fixed frequency

with variable tuning elements, the load impedance shall

be provided as a function of the tuning element

positions. In addition, the efficiency of the matching

network shall be provided as a function of the tuning

element positions. The information shall be provided in

tabular form. The increment of the tuning element

positions shall be in steps equal to or less than 10% of

the full range. For example, a voltage increment of 1

volt or less shall be used in the case where the full

range of the tuning element position is 10 volts. A plot

providing an example of the real part of the load

transformed to 50 ohms by the matching network as a

function of tuning element position indicator is shown

in Figure 1 and a plot of the reactive part of the load

impedance is shown in Figure 2. A plot of the power

efficiency is shown in Figure 3. An example of data to

be provided in tabular form is shown in Table 1. The

required uncertainty of the magnitude of the impedance

is  1.5%, the required uncertainty in the phase angle of

the impedance is  0.35°, and the required uncertainty

of the power efficiency is  2.0%. For example, a load

impedance of 2.0 – j20 ohms would have an uncertainty

in the real part of  0.15 ohms and an uncertainty in the

reactive part of  0.32 ohms.

7.4.5 For matching networks run at a variable

frequency with fixed tuning elements and/or tap points,

the efficiency and load impedance as a function of its

output parameters (frequency, input impedance, and tap

point value (if any)) shall be provided. The information

shall be provided in tabular form. The increment of the

output parameters shall be in steps equal to or less than

10% of the full range. For example, if the operating

frequency parameter is given as an output voltage, a

voltage increment of 1 volt or less shall be used in the

case where the full range of the output parameter is 10

volts. The required uncertainty of the magnitude of the

impedance is 

1.5%, the required uncertainty in the

phase angle of the impedance is  0.35°, and the

required uncertainty of the power efficiency is  2.0%.

7.4.6 The tuning element positions/values for each

matching network (of the same type/model) shall be

adjusted to provide consistent efficiency and matching

network input impedance when the matching network is

connected to a fixed load impedance. The load

impedance used shall be one that is typically

encountered by the matching network during processing

and/or shall be an impedance that is near the mid-range

of the tuning space (e.g., 2 – j20 ohms). A simple way

to ensure network-to-network consistency is to adjust