Technology for А₃В₅ semiconductors and devices on their base

The following basic epitaxial structure crystallization technologies are utilizing at SRC «Carat» for fabrication of semiconductor materials:

- Liquid phase epitaxy (LPE) in high- and low-temperature modes;

- Chloride gas process for epitaxy.

The main products:

- Epitaxial structures on the base of GaAs for Hall sensors;

- Epitaxial structures on the base of GaAs/AlGaAs for heterolaser and LEDs operating in 630-810 nm spectral band;

- Epitaxial structures of InP/InGaAsP for LEDs operating in 1000-1010 nm spectral band;

- Epitaxial structures of GaAs/AlGaAs/InGaP for photoelectric converters of solar energy;

- Photoelectric converters on the base of GaAs/AlGaAs,GaAs/AlGaAs/InGaP heterostructures with efficiency 20-22% at АМ 1.5 including solar sell concentrators.

 

Products are manufacturing in LPE furnaces on the base of modernized machines SDO 125/3, SDOM, Evars (in-house design) and vapor-phase epitaxy «Micro» (in-house design).

 

Recently the MOS hydride epitaxy facility «Discovery 180LDM» (Veeco, USA) has been put into operation together with JSC «Scientific and Industrial Concern «Nauka» that allowed to start technology for fabrication of state-of-art nanosized epitaxial structures for high-brightness LEDs, tandem photoelectric converters with efficiency 35-40%, laser structures, etc.

 

Photolithography

Fabrication technology for conductor lines on semiconductor surfaces metallized with Cr, Cu, brass, SiO2, Au, Ni with 5 μm resolution has been developed at photolithography laboratory.

 

The laboratory’s specialists have developed a technology for fabrication of interdigital transducers that is widely used for production of acousto- and optoelectronic devices. Manufacturing technologies for chips based on GaAs and InP epitaxial structures, CdHgTe substrates which are using at fabrication of microwave electronic devices, photodetectors, LEDs, laser wafers, etc.

 

The laboratory is located in class «100» in-house designed microclimate module ММКІ-32(001). Laboratory facility gives possibility to carry out contact photolithography processes onto substrates with sizes from 10х10 mm till 240х240 mm and thickness from 1 mm till 20 mm.

 

Narrow gap semiconductors

Laboratory of the narrow gap А²В⁶ semiconductors electrophysic and optic investigations is equipped with:

- automatized complex for investigation of electrophysical parameters of semiconductors with own software for parameter determination by mobility discrete spectrum method;

- automatized complex for investigation of optical and photoelectrical properties of semiconductors (photoluminescence, photoconductivity, transmission and absorption) in 0.2…15 μm spectral band and 77-300 К temperature range;

- photolithography line located in class «100» clean room;

- ion beam milling facility.

 

The laboratory’s scientists and specialists have carried out comprehensive investigations of ion milling influence on properties of Cd_xHg_1-xTe solid solutions. As result it has been revealed and formulated the main regularities of the materials property modification during ion milling process. It has given possibility to validate a physical basis for application the ion milling as a method for formation of p-n junctions at fabrication of IR photodiodes based on Cd_xHg_1-xTe. Basing on this technology the laboratory is now developing new types of CdHgTe IR photodiodes.

 

Vitreous semiconductors and their alloys

The SRC «Carat» is carrying out a comprehensive investigation of halcogenide glasses (HG) as a prospective material for application in modern optoelectronics, photonics, telecommunications, acoustooptics, xerography, lithography, etc.

 

Due to high transparency of optical fiber on the base of HG in IR spectral band (overlapping bands of both telecommunication windows 3…5 and 8…12 μm) vitreous semiconductors could be potentially used in civil, medical and military areas as chemical sensors, information record devices, IR optofibers, optical switches, etc.

 

High sensitivity of halcogenide glass to external influence like to light, ionizing radiation or thermal treatment defines practical advantages of HG over other crystal and glassy-like materials during their utilization in the above mentioned areas.