Polycrystalline Silicon for Integrated Circuit Applications

Recent years have seen silicon integrated circuits enter into an increasing number of technical and consumer applications, until they now affect everyday life, as well as technical areas. Polycrystalline silicon has been an important component of silicon technology for nearly two decades, being used first in MOS integrated circuits and now becoming pervasive in bipolar circuits, as well. During this time a great deal of informa tion has been published about polysilicon. A wide range of deposition conditions has been used to form films exhibiting markedly different properties. Seemingly contradictory results can often be explained by considering the details of the structure formed. This monograph is an attempt to synthesize much of the available knowledge about polysilicon. It represents an effort to interrelate the deposition, properties, and applications of polysilicon so that it can be used most effectively to enhance device and integrated-circuit perfor mance. As device performance improves, however, some of the proper ties of polysilicon are beginning to restrict the overall performance of integrated circuits, and the basic limitations of the properties of polysili con also need to be better understood to minimize potential degradation of circuit behavior.

Contenu
1 Deposition.- 1.1 Introduction..- 1.2 Thermodynamics and kinetics.- 1.3 The deposition process.- 1.4 Gas-phase and surface processes.- 1.5 Reactor geometries.- 1.6 Reaction.- 1.7 Deposition of doped films.- 1.8 Step coverage.- 1.9 Enhanced deposition techniques.- 1.10 Summary.- 2 Structure.- 2.1 Nucleation.- 2.2 Surface diffusion and structure.- 2.3 Evaluation techniques.- 2.4 Grain structure.- 2.5 Grain orientation.- 2.6 Optical properties.- 2.7 Etch rate.- 2.8 Stress.- 2.9 Thermal conductivity.- 2.10 Structural stability.- 2.11 Epitaxial realignment.- 2.12 Summary.- 3 Dopant Diffusion and Segregation.- 3.1 Introduction.- 3.2 Diffusion mechanism.- 3.3 Diffusion in polysilicon.- 3.4 Diffusion from polysilicon.- 3.5 Interaction with metals.- 3.6 Dopant segregation at grain boundaries.- 3.7 Summary.- 4 Oxidation.- 4.1 Introduction.- 4.2 Oxide growth on polysilicon.- 4.3 Conduction through oxide on polysilicon.- 4.4 Summary.- 5 Electrical Properties.- 5.1 Introduction.- 5.2 Undoped polysilicon.- 5.3 Moderately doped polysilicon.- 5.4 Grain-boundary modification.- 5.5 Heavily doped polysilicon films.- 5.6 Minority-carrier properties.- 5.7 Summary.- 6 Applications.- 6.1 Introduction.- 6.2 Silicon-gate technology.- 6.3 Nonvolatile memories.- 6.4 High-value resistors.- 6.5 Fusible links.- 6.6 Polysilicon contacts.- 6.7 Bipolar integrated circuits.- 6.8 Device isolation.- 6.9 Trench capacitors.- 6.10 Polysilicon diodes.- 6.11 Polysilicon transistors.- 6.12 Polysilicon sensors.- 6.13 Summary.