Physical Bases of Work of Photo Receivers Based on Silicides

Elchin Ahmed Kerimov,Sevinj Nadir Musaeva

doi:10.11648/j.sjc.20200804.11

Abstract

The creation of high-quality high-speed semiconductor devices and integrated circuits requires the introduction of new materials into the technology for their manufacture. The most promising of them are silicides-silicon compounds with more electropositive elements. These compounds can be obtained as a result of a solid phase reaction at a temperature in the range of about one to half the melting point of this metal on an absolute scale. Silicides have a high conductivity of a metallic nature, high temperature stability, and surpass in these properties any heavily doped semiconductor layer. The use of polysilicon as a material for gates and connecting lines providing a layer resistance of 20 Ohms/□ allowed us to reduce the minimum dimensions of the elements of devices to 25 microns. Methods were proposed for the formation of silicide films, as well as technological processes necessary for the manufacture of semiconductor devices and microcircuits with their application, which allowed us to start developing devices with a minimum element size of 1 μm and to begin their industrial production. The stable and reliable characteristics of platinum-silicon silicide (PtSi-Si) contacts have led to the widespread use of silicides as materials for ohmic contacts, gates in metal-oxide-semiconductor (MIS)-transistors, materials for storing optical information, photodetectors operating in IR-spectral regions, etc. The Si-2p band has an asymmetric shape; the structure of valence states differs from metallic ones.

Highlights

The conclusion is drawn about the strong interaction between Si and Pt up to coatings of 40 monolayers
The kinetics of the formation of platinum silicide in particular and the effect of impurities on the formation of PtSi were intensively studied by such methods as Auger spectroscopy, X-ray diffraction, Rutherford backscattering of H+ions, and scanning electron microscopy
It was found that in addition to the annealing temperature, impurities play an important role in the solid-phase growth of silicides, slowing down the reaction of their formation

Summary

Introduction

The conclusion is drawn about the strong interaction between Si and Pt up to coatings of 40 monolayers. The influence of nitrogen atoms located in the surface Si layer and annealing temperature on the growth pattern of platinum silicide layers was studied [1,2,3,4,5]. The growth rate of silicides in the presence of a protective layer located on top of the platinum layer during annealing was higher compared to the growth of silicide with an unprotected platinum film on silicon Such a layer protected the metal from the undesirable effect of small doses of oxygen and other contaminants contained in the working medium [6,7,8,9]. It was found that the presence of oxygen in the platinum film determines the reaction rate and phase growth, namely, the diffusion process of the formation of PtSi and Pt2Si and changes the phase sequence. Where, the second term is the difference between the work function of the metal and the electron affinity of the semiconductor

Еxperimental Part

The Theoretical Part

The Discussion of the Results

Basic Conclusions