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SEMI E43-0301 © SEMI 1995 , 2001 15 standard requirements . The IEC 61000-4-2, 19 96 (forma lly-801- 2,1992) standard uses direct contact or air disch arge to the system un der test and is a different procedure from the …

SEMI E43-0301 © SEMI 1995, 2001 14

RELATED INFORMATION 3

ESD DAMAGE SIMULATORS

NOTE: This related information is not an official part of this standard. However, it contains relevant information for using the

standard in situations commonly encountered with semiconductor manufacturing facilities and equipment. Determination of the

suitability of the material is solely the responsibility of the user.

R3-1 ESD Damage Simulators

R3-1.1 ESD Simulators are used to replicate ESD

events. Common types used to characterize

semiconductor devices and equipment include:

• Component Level HBM ESD Simulator.

• Component Level MM ESD Simulator.

• Component Level CDM ESD Simulator

• System Level HBM/metal ESD Simulator

R3-1.2 The component level HBM ESD Simulator

represents the parameters agreed upon for a standard,

which represents the discharge from a typical human

body. These parameters are 1500 ohms and 100 pF for

the representative resistance and capacitance

respectively of the human body.

R3-1.3 The component level MM ESD Simulator

represents the parameters agreed upon for a standard,

which represents the discharge from a charged metallic

arm of a machine (automatic handler etc). These

parameters are 200 pF and zero resistance for the

representative capacitance and DC resistance

respectively of the machine. We note here that the

resulting waveform is dependent on the impedance of

the circuity.

R3-1.4 The component level CDM ESD Simulator

represents the parameters agreed upon for a standard,

which represents the discharge from a charged device.

These parameters are defined by the resulting

waveform and depend almost exclusively on the

capacitance, resistance and inductance of each device

relative to ground. These parameters must not be

confused with the equipment parameters, which affects

the resulting waveform.

R3-1.5 The system level HBM/metal ESD Simulator

represents the parameters agreed upon for a standard,

which represents the discharge from a human holding a

metallic instrument. These parameters are the lower

resistance 350 ohms and 150 pF for the representative

resistance and capacitance respectively of the human

holding a metallic instrument. Note here that the

waveform is greatly affected by the equipment

parasitics.

R3.1.6 The above component level ESD simulators

have also been used in simulating ESD damage to

tooling, such as reticles and photomasks. This

simulation is left to user discretion.

R3-2 Summary of procedures

R3-2.1 HBM ESD Simulator-component level — The

procedure for using this simulator to stress test devices

or wafers is based upon the standard requirements.

ANSI and the ESD Association approved the HBM

standard, ESD STM5.1, which contains a specific

device pin combination sequence for stress testing.

This test procedure is generally referred to as a Pin to

Ground test since one pin is always grounded while the

selected second pin is stressed. Calibration before use

requires added equipment components like a current

probe, high bandpass cable, a short wire, a 500 ohm

resistor and a very high band width waveform

recorder/digitizer.

R3-2.2 MM ESD Simulator-component level — The

procedure for using this simulator to stress test devices

or wafers is based upon the standard requirements. The

ESD S5.2 approved MM standard specifies a specific

device pin combination sequence for stress testing.

This test procedure is also generally referred to as a Pin

to Ground test since one pin is always grounded while

the selected second pin is stressed. This procedure is

exactly the same as for HBM. Calibration before use

requires added equipment components like a current

probe, high bandpass cable, short wire, a 500 ohm

resistor and a very high band width waveform

recorder/digitizer.

R3-2.3 CDM ESD Simulator-component level — The

procedure for using this simulator to stress test devices

or wafers is based upon the standard requirements. The

ESD STM 5.3.1 approved CDM standard does not use a

pin combination procedure. Here the device sits on a

charge plate (CP) “dead-bug” style (package on CP and

leads/pins vertical) and each pin is discharged

successively after each charge to the device package.

This procedure is different from that of HBM and MM.

Calibration before use requires added equipment

components like a capacitance/inductance calibrator,

high bandpass cable and a very high band width

waveform recorder/digitizer.

R3-2.4 HBM-metal Simulator- system level — The

procedure for using this hand-held simulator for testing

systems (ATE testers, Automatic handlers, computers,

printers, ESD Simulators etc) is based upon the

SEMI E43-0301 © SEMI 1995, 200115

standard requirements. The IEC 61000-4-2, 1996

(formally-801-2,1992) standard uses direct contact or

air discharge to the system under test and is a different

procedure from the other three procedures mentioned

above. Calibration before use requires the use of a very

large vertical ground plane (at least 4 ft by 4 ft square),

a high BW current probe, cables and high bandwidth

waveform recorder/digitizer.

R3-3 Industry Classifications

R3-3.1 HBM classification

1. < 250 volts

2. 250 to < 500

3. 500 to < 1000

4. 1000 to < 2000

5. 2000 to < 4000

6. 4000 to < 8000

7. = or > 8000

R3-3.2 MM classification

1. M1 < 100

2. M2 100 to < 200

3. M3 200 to < 400

4. M4 400 to < 800

5. M5 = or > 800

R3-3.3 CDM classification

1. C1 < 125

2. C2 125 to < 250

3. C3 250 to < 500

4. C4 500 to < 1000

5. C5 1000 to < 2000

6. C6 = or > 2000

R3-3.4 Hand-Held Metal HBM classification

Direct Contact Discharge

Voltage Current

1. 2,000 12.0 amps

2. 4,000 24.0

3. 6,000 36.0

4. 8,000 48.0

Air Discharge

Voltage Current

1. 2,000 15.0 amps

2. 4,000 25.0

3. 6,000 30.0

4. 10,000 35.0

5. 15,000 52.0

Note that the currents for the same voltage level are not

the same for contact versus air discharge.

SEMI E43-0301 © SEMI 1995, 2001 16

RELATED INFORMATION 4

OTHER METHODS FOR DETECTING STATIC CHARGE AND ESD

EVENTS IN EQUIPMENT

NOTE: This related information is not an official part of this standard. However, it contains relevant information for using the

standard in situations commonly encountered with semiconductor manufacturing facilities and equipment. Determination of the

suitability of the material is solely the responsibility of the user.

R4-1 Introduction

R4-1.1 Static charge generation is unavoidable

whenever materials come in contact. Without a static

control program, the problems caused by static charge

are also unavoidable. The most common problem

caused by static charge is electrostatic discharge (ESD).

ESD results in damaged semiconductor ICs, photomask

defects, magneto-resistive (MR) read head defects in

disk drives, and failures of the drive circuits for flat

panel displays (FPD). ESD also creates a significant

amount of electromagnetic interference (EMI). Often

mistaken for software errors, EMI resulting from ESD

interrupts the operation of production equipment. This

is particularly true of equipment depending on high-

speed microprocessors for control. Results include

unscheduled downtime, increased maintenance

requirements, and frequently, product scrap.

Technology trends to smaller device geometries, faster

operating speeds, and increased circuit density make

ESD problems worse.

R4-1.2 For many years static control programs

concentrated on protecting components from the charge

generated on the personnel that handled them. Many

static control methods were devised to control the

charge on people including wrist and heel straps,

dissipative shoes and flooring, and garments.

Increasingly, however, the production of electronic

components is done by automated equipment, and

personnel never come into contact with the static-

sensitive devices. Solving the ESD problem means

assuring that ESD events do not occur in the equipment

used to manufacture and test electronic components.

R4.2 Static Control in Equipment

R4-2.1 An effective static control program in

equipment starts with grounding all materials that might

come close to, or in contact with the static sensitive

components. This prevents the generation of static

charge on machine components and eliminates them as

a source of the charge creating ESD events. Care must

be taken in a grounding program to assure that moving

equipment parts remain grounded when they are in

6 Levit, L. et al, “It’s the Hardware. No, Software. No, It’s ESD! ”,

Solid State Technology, May 1999, Pennwell Publishing Company,

98 Spit Brook Road, Nashua NH 03062.

motion. In some cases, static dissipative materials may

be substituted for conductive materials where

flexibility, thermal insulation, or other properties not

available in conductive materials are needed. If

charging of components is unavoidable, static

dissipative materials may be used to slow the resulting

discharges and prevent component damage.

R4-2.2 Most semiconductors use insulating packaging

materials such as ceramics and epoxy. Handling these

insulating materials inevitably generates static charge,

and this charge cannot be removed by grounding the

materials. If charge generation is unavoidable, the only

effective method of neutralizing the charge on

insulators or isolated conductors is to use air ionization.

Ionizers are typically mounted in the load stations and

process chambers of the automated equipment to

neutralize the static charge.

R4-3 Verifying Equipment Static Control

R4-3.1 A static control program begins when the

automated equipment is designed by the OEM, and then

continues throughout the lifetime of the equipment.

Two basic issues need to be demonstrated. First, are all

components in the product-handling path connected to

ground? Second, as the product passes through the

equipment, is it handled in a way that does not generate

static charge above an acceptable level on the

component? ESD Association Standard Practice,

EOS/ESD SP 10.1-1999

. This document contains test

methods to verify the integrity of the ground path to

equipment parts, as well as to determine if the product

is being charged during its passage through the

equipment. The test methods are applicable during the

original design of the equipment and during acceptance

testing by the end user.

R4-3.2 While the test methods of EOS/ESD SP10.1-

1999 can also be used for periodic verification of the

equipment performance, they have one drawback. The

automated equipment must be taken off-line to do the

testing. This means that there is lost production time,

and often the periodic testing is eliminated to maintain

product throughput. Other test methods are available

7 EOS/ESD SP10.1 - 1999 “Standard Practice for Protection of

Electrostatic Discharge Susceptible Items - Automated Handling

Equipment”, ESD Association, 700 Turin Road, Rome NY 13440.