Metal Impurities in Silicon- and Germanium-Based Technologies

Preface
List of Symbols             
List of Greek Symbols                 
List of Acronyms                                                                                               

1.                   Introduction

References 2.                   Basic Properties of Metals in Semiconductors (20 p) 

2.1                 Diffusivity

2.2                 Solubility

2.3                 Segregation

2.4                  Precipitation and Gettering 2.5                 Electrical Properties

2.5.1        Shockley Read Hall Model

2.5.2           Activation Energy

2.5.3           Lifetime and capture cross-section 2.5.4           Leakage current

References 3.                  Sources of Metals in Si and Ge Processing (40 p)

3.1            Crystal Growth

3.1.1        Micro-electronics grade crystalline substrates

3.1.2        Substrates for PV applications

3.2              Wafer Handling

3.3               Wafer Cleaning

3.4              Lithography and Patterning

3.4.1        Resist Processing and Stripping

3.4.2        Wet Etching

3.4.3        Dry Etching

3.5              Ion Implantation

3.6        Thermal Processing 3.6.1         Diffusion processes

3.6.2         Gate Dielectrics

3.6.3         Deposition Techniques

3.7              Silicidation and Metallization 3.8              Chemical Mechanical Polishing

3.9              Through Silicon Vias Processing

References

4.              Characterization and Detection of Metals in Silicon and Germanium (30 p)

4.1           Chemical Techniques

4.1.1.       Electron Spin Resonanc<

4.1.2.       SIMS and TOFSIMS

4.1.3.        X-ray analysis (TXRF/EDX)

4.1.4.         Neutron Activation Analysis

4.1.5.         Structural Charactization (precipitates):

4.2.1           Scanning and transmission Electron Microscopy (SEM –TEM)

4.2.2           Optical Spectroscopy (AFM) & Defect Etching  (haze test)

4.2.3            Scanning PL technique 4.3                 Electrical Characterization

4.3.1              Hall Effect versus Temperature

4.3.2              Deep-Level Transient Spectroscopy (DLTS);

4.3.3               Lifetime Measurements

4.3.3.1  MOS Zerbst Technique 4.3.3.2   Surface Photo Voltage (SPV)

4.3.3.3  Microwave Absorption Analysis (MWA)

4.3.3.4  Electrolytic Methods (Elymat) 4.3.3.5  Ion drift studies

4.4                 Metal Contamination analysis methodology

References

5.      Electrical activity of Metals in Si and Ge (50 p)

5.1                    Properties of Fe (DLTS levels and lifetime)

5.2                    Properties of Cu

5.3                    Properties of Ni 5.4                    Properties of other TM (Ti, Co, Cr, Mn,..)

5.5                    Properties of Au, Pt and Ag

5.6                    Properties of Refractory Metals (Mo, W,…)

5.7                    Properties of Rare Earths

References

6.      Impact of metals on silicon devices and circuits (30 p)

 

6.1            P-n junction leakage and Lifetime Control

6.2            MOS Interface States and Dielectric Breakdown

6.3            Reliability Aspects

6.4            Charge Coupled Devices (CCDs) and CMOS Imagers

6.5            Solar Cell Efficiency

6.6            Impact on Circuit Yield

References 7.      Gettering and Passivation of Metals in Silicon and Germanium (30 p)

7.1            Gettering Strategies 

7.4             Back Damage Gettering

                  7.4.1   Mechanical Stress (poly-Si, Si₃N₄, sandblasting, high doping layer)                   7.4.2   Ion Implantation

7.5             Front Side Gettering                   7.5.1   Ion Implantation

                  7.5.2   Proximity Gettering

                  7.5.3   Nano Cavities

7.6             Al Gettering

7.7             Hydrogen Passivation of Metals

References

8.      Modeling and Simulation of Metals in Silicon and Germanium (15 p)

8.1             First Principles Analysis

8.2.            Density Functional Theory (DFT)

8.3             Modeling/Simulation Metals

8.4             Gettering Simulation

References

Conclusions