To illustrate the above procedure, consider the and R charts developed for the hard-bake process in Example 6.1. These charts were based on a sample size of five wafers. Suppose that since the process...

TABLE 6.1

Flow Width Measurements (microns) for the Hard-Bake Process

Wafers

Sample Number

1

2

3

4

5

R_i

1

1.3235

1.4128

1.6744

1.4573

1.6914

1.5119

0.3679

2

1.4314

1.3592

1.6075

1.4666

1.6109

1.4951

0.2517

3

1.4284

1.4871

1.4932

1.4324

1.5674

1.4817

0.1390

4

1.5028

1.6352

1.3841

1.2831

1.5507

1.4712

0.3521

5

1.5604

1.2735

1.5265

1.4363

1.6441

1.4882

0.3706

6

1.5955

1.5451

1.3574

1.3281

1.4198

1.4492

0.2674

7

1.6274

1.5064

1.8366

1.4177

1.5144

1.5805

0.4189

8

1.4190

1.4303

1.6637

1.6067

1.5519

1.5343

0.2447

9

1.3884

1.7277

1.5355

1.5176

1.3688

1.5076

0.3589

10

1.4039

1.6697

1.5089

1.4627

1.5220

1.5134

0.2658

11

1.4158

1.7667

1.4278

1.5928

1.4181

1.5242

0.3509

12

1.5821

1.3355

1.5777

1.3908

1.7559

1.5284

0.4204

13

1.2856

1.4106

1.4447

1.6398

1.1928

1.3947

0.4470

14

1.4951

1.4036

1.5893

1.6458

1.4969

1.5261

0.2422

15

1.3589

1.2863

1.5996

1.2497

1.5471

1.4083

0.3499

16

1.5747

1.5301

1.5171

1.1839

1.8662

1.5344

0.6823

17

1.3680

1.7269

1.3957

1.5014

1.4449

1.4874

0.3589

18

1.4163

1.3864

1.3057

1.6210

1.5573

1.4573

0.3153

19

1.5796

1.4185

1.6541

1.5116

1.7247

1.5777

0.3062

20

1.7106

1.4412

1.2361

1.3820

1.7601

1.5060

0.5240

21

1.4371

1.5051

1.3485

1.5670

1.4880

1.4691

0.2185

22

1.4738

1.5936

1.6583

1.4973

1.4720

1.5390

0.1863

23

1.5917

1.4333

1.5551

1.5295

1.6866

1.5592

0.2533

24

1.6399

1.5243

1.5705

1.5563

1.5530

1.5688

0.1156

25

1.5797

1.3663

1.6240

1.3732

1.6887

1.5264

0.3224