Структура та фізичні властивості кремнійових композицій з розупорядкованими шарами

 

У дисертації досліджено структуру і фізичні властивості кремнійових композицій і приладів із розупорядкованими шарами імплантованого і пористого кремнію. На широкому матеріалі із використанням джерел різнорідної часової приналежності у роботі розглянуті антивіддзеркалювані та гетеруючі властивості шарів імплантованого та пористого кремнію. Проведено комплексні дослідження структурних і фізичних властивостей композицій від умов їх формування. Проведено електрофізичні дослідження отриманих фотоелектричних перетворювачів і транзисторних структур.

Ключові слова: розупорядковані шари, композиція, пористий кремній, імплантований кремній, дефекти структури, вектор Бюргерса, фотоелектричний перетворювач, транзисторна структура.

 

В диссертации исследованы структура и физические свойства кремниевых композиций и приборов с разупорядоченными слоями, такими как слои имплантированного и пористого кремния. На обширном материале с использованием разновременных источников в работе рассмотрены антиотражающие и геттерирующие свойства слоев имплантированного и пористого кремния. Проведены комплексные исследования структурных и физических свойств композиций от условий их формирования. Проведены электрофизические исследования полученных фотоэлектрических преобразователей и транзисторных структур.

Ключевые слова: разупорядоченные слои, композиция, пористый кремний, имплантированный кремний, дефекты структуры, вектор Бюргерса, фотоэлектрический преобразователь, транзисторная структура.

 

The results of disordered layers classification in semiconductors are presented. It is understood from published data, that the main methods of layers shaping is an anode etching and implantation by high energy ions.

It is presented the review of results of theoretical and experimental investigation of wide-zone semiconductor – isolator – narrow-zone semiconductor photoelectric converters shaping.

The advantage of using fine ITO-films at fabrication of photoelectric converters is shown. The specific role disordered layers as anti-reflecting covering  (especially for porous silicon)  is specified. The data of optical and electrophysical characteristics of porous silicon depending on used equipment and conditions of shaping are discussed. It is shown that in modern domestic research practical is missing the experience of photoelectric converters fabrication base on wide-zone semiconductor  (ITO) - isolator – -porous silicon compositions.

List of methods of gettering defects is presented for active areas of crystal.

In etching process contents of hydrofluoric acid in solution change from 10% to 49%. The thickness of porous silicon layers was from 0, 5 – 14 m.

The porous silicon layers shaping was before epitaxial layer growth at anode current density 4 ìÀ/cm2.

The particularities of factor of absorption determination and reflection factor calculation, which was used in the work is presented.

The techniques of layers thickness, resistivity and surface resistance, spectral, current-voltage and capacitance-voltage characteristics measurement for photoelectric converters and study of porous silicon density are presented.

The study of disordered layers structure of silicon was carried by means of optical, electronic raster and x-raying microscopy.

Density of defects in active areas of transistor structure was measured by means of selective etching. The technique of electronic-microscopic study for defects of structure in laminated silicon compositions was presented.

The maximum amount of pores  (4*108 – 8*109 sm-2)  corresponds to the diameter range 40-80Е.

The microdifractive pictures shows that samples with porous layer have the reflexes, which have charge of presence of amorphous phase.

The dependencies of InxSnyO film surface resistance from percent contents SnCl4 (5H2O)  in solution were measured. It is stated that under small concentrations of tin in mixtures its atoms substitute the atoms an india in structure of film. However, when SnCl4 (5H2O)  concentrations increase in the solution, contents of phase SnO2 increases in composition of film InxSnyO, that cause reduction of free carriers concentrations and reduction of conduction.

The calculation of ITO layer reflection factor from thickness was carried out. The least size of reflection factor has covering with thickness from 500Е to 800Е within the range of waves lengths 0, 42-0, 61 m.

The forming of defects in nearsurface areas of silicon under ion implantation was explored. Their own sizes and site can change in process of lattice defects annealing. The nature of defects is basically defined by the type of ions, dose and energy of implantation, as well as thermal processing conditions.

Gettering characteristics of porous silicon, got before epitaxy was measured. The results show that porous silicon thickness increase leads to amorphous silicon thickness increasing and both polycristalline and amorphous phases formation.

When the density of porous silicon changes from 1, 92 g/sm3 to 1, 48 g/sm3, the epitaxial film defects density inheres in borders from 8. 0*100sm-2 to 1. 2*107 sm-2.

It notes that in interval of porous silicon density from 1, 54 g/sm3 to 1, 62 g/sm3 density of defects in epitaxial layer changes from 1, 1*106 sm-2 to 4, 0*105 sm2. In this interval density of defects in nearby areas an epitaxial film on n+-layer inheres in borders 8, 0*100sm-2 – 1, 1*101sm-2.

Also was researched dependency of defect density from the operational procedure of fabrication of transistor compositions with different doses of implantations 2*1014-7*1015ñì-2 ions of argon when forming multifunction gettering.

The defect density reduction 1, 45*101 sm-2 exists if implantation dose is 7*1014 sm-2. This enables control a quality transistor structure depending on implantation dose.

In work is shown that efficient control electrophysical parameters of transistor composition is possible also by making the gettering sewers both in volume epitaxial layer and on its surface in places of multilevel isolation shaping.

 

Key words: disordered layers, composition, porous silicon, implanted silicon, defects of structure, vector Burgers, photoelectric converter, transistor structure.