GaN/sapphire wafers

 1

Description

Maximum Permissible

Inspection Level

1

Defects @ 50x

per spec

per 2" wafer

1.1

Voids

0

per spec

per 2" wafer

1.3

Large Defects

0

per spec

per 2" wafer

Large defects are defined as any defect >50um in width and >200nm in height. Large defects are visable to the naked eye under white light.

1.4

Scratches

edge ok

per spec

per 2" wafer

1.5

Contamination

0

per spec

per 2" wafer

1.6

Defects (Particles, Pits)

< 200

per spec

per 2" wafer

Microscope images are taken from three locations: 1) 5mm from the top edge, 2) center of wafer and 3) 5mm from bottom flat.  The total number of defects at these three location combined should be equal or less than 9 defects for the inspection to pass.

2

Cracks

0

count

per 2" wafer

3

BOW

< 50um

per spec

per 2" wafer

4

Resistivity

< 20 milli-ohm cm

per spec

per 2" wafer

5

Surface Roughness

< 12nm Ra (3 profilometer scans - 1mm length each)

per spec

per 2" wafer

6

Fishscale

Not allowed

per example

per 2" wafer

2.Substrate spec

For use with SSP

2.10

Orientation:

c-plane (0001)

2.11

Offcut:

0.2 +/- 0.1 degrees (M-plane)
0 +/- 0.1 degrees (A-plane)

2.12

Diameter:

2 inch (50.8 +/- 0.25mm)

2.13

Thickness:

430 +/- 20um

2.14

Primary flat:

16 +/- 1mm

2.15

Flat location:

A-plane (1120) +/- 0.3 degrees

2.16

Front side finish:

EPI Polish Ra <0.3nm

2.17.1

Pattern Bottom Diameter:

NA

2.17.2

Pattern Pitch:

NA

2.17.3

Pattern Height:

NA

2.17.4

Pattern Type:

NA

2.18

Back side roughness

Ra 1.0 +/- 0.5um

2.19

Both sides beveled

Rounded / Chamfering Angle (C) = 45°

2.20

TTV

<10um

2.21

Bow

<10um

2.22

Warp

<10um

2.23

Edge Profile

SEMI Spec M1 or equivalent

2.24

Pits

<50 per 2-inch wafer

2.25

Particles

<150 per 2-in wafer

2.26

Large Defects > 50um

0 per 2-in wafer

2.27

Pattern Defects:

NA

2.28

Laser marking:

Back side - Semi Spec M1 or equivalent

All wafers IDs start with two (2) letters followed by seven (7) numbers

3.n-GaN spec

3.10

Total GaN layer thickness:

4um-6 um ( 2um nGaN included )

3.11

n-GaN: Si layer thickness:

2um-4um

3.12.1

GaN Thickness uniformity:

<2%

3.12.2

Edge exclusion for GaN thickness uniformity:

1mm

3.13

XRD FWHM:

 < 350" for (102) and < 300" for (002)

3.14

Si doping level:

5E18 - 1E19cm-3

3.15.1

Sheet Resistance:

<50Ω/sq

3.15.2

Resistivity:

<20mΩ-cm

3.16

Surface roughness:

< 12nm Ra (3 profilometer scans - 1mm length each)

3.17

Bow (measure with 1 mm edge exclusion)

<50um

3.18.1

Edge exclusion for defects:

2mm

3.18.2

Defects: Particles and Pits

< 200 per 2-inch wafer

3.18.3

Defects: Large Defects > 50um

0 per 2-in wafer

3.19

Fishscale

not allowed  

SEMI Standards

SEMI STANDARDS

M1

 Specifications for Polished Single Crystal Silicon Wafers

M12

 Specification for Serial Alphanumeric Marking of the Front Surface of Wafers

M65

 Specifications for Sapphire Substrates to Use for Compound Semiconductor Epitaxial Wafers

MF26

 Test Method for Determining the Orientation of a Semi-conductive Single Crystal

MF523

 Practice for Unaided Visual Inspections of Polished Silicon Wafer Surfaces

MF533

 Test Method for Thickness and Thickness Variations of Silicon Wafers

MF534

 Test Method for Bow of Silicon Wafers

MF657

Test Method for Measuring Warp and Total Thickness Variation on Silicon Wafers by Noncontact Scanning

MF671

 Test Method for Measuring Flat Length on Wafers and Other Electronic Materials

MF847

 Test Method for Measuring Crystallographic Orientation of Flats on Single Crystal Silicon Wafers by X-ray Techniques

MF928

 Test Method for Edge Contour of Circular Semiconductor Wafers and Rigid Disk Substrates

MF1152

 Test Method for Dimensions of Notches on Silicon Wafers

MF1530

 Test Method for Measuring Flatness, Thickness, and Total Thickness Variation on Silicon Wafers by Automated Non-contact Scanning

MF2074

 Guide for Measuring Diameter of Silicon and Other Semiconductor Wafers

ASQC Standard[1]

ASQ Standards

ANSI/ASQC Z1.4

 Sampling Procedures and Tables for Inspection by Attributes

ASTM Standard[2]

ANSI STANDARDS

E122

 Standard Practice for Calculating Sample Size to Estimate, with Specified Precision, the Average for a Characteristic of a Lot or Process

JIS Standards[3]

JIS STANDARDS

H 0611

 Methods of measurement of thickness, thickness variation and bow of silicon wafer

H 0614

 Visual inspection for silicon wafers with specular surfaces