• Email
  • Drucken

Polysilicon Technology

SiTec provides complete integrated technology packages for:

Trichlorosilane (TCS) Synthesis and Distillation for Direct Chlorination (DC) process

This well proven and established process is used by world leading producers. TCS is produced from metallurgical silicon and hydrogen chloride (HCl) according to the reaction:

Si + 3 HCl → HSiCl(TCS) + H2  

Major advantages of Direct Chlorination are low temperature and low pressure of the process as well as high TCS yield.

Download Datasheet

Trichlorosilane (TCS) Synthesis and Distillation for Hydrochlorinaton (HC) process

The process has become popular in the industry, due to combination of TCS synthesis and STC-TCS conversion in one technological step. TCS is produced from metallurgical silicon, STC and hydrogen according to the reaction:

Si + 3 SiCl4 (STC) + 2 H2 → 4 HSiCl3 (TCS)

The reaction takes place at high temperature and pressure. 

Download Datasheet

Monosilane Production

Monosilane is an alternative feedstock for production of high purity (>9N) polysilicon. Our technology solution for monosilane production includes TCS synthesis, monosilane synthesis via TCS redistribution followed by fine purification of monosilane.

The most cost efficient way to produce polysilicon from monosilane is deposition in FBR (Fluidized Bed Reactor).

Monosilane is an essential material for the semiconductor industry. The monosilane technology of SiTec gives customers the flexibility to produce bulk polysilicon material or monosilane depending on market situation and to secure their commercial success.

TCS Siemens CVD Technology

The TCS/H2 mixture is injected into the reactor, where TCS decomposes in the gas phase at high temperature to silicon onto silicon rods. Cost efficient polysilicon production requires high reactor capacity, low electricity consumption and optimized reactor design. Due experience in realized polysilicon projects and the optimized design of the CVD Polysilicon Reactor, SiTec´s TCS Siemens CVD Technology is proven to have the lowest operating cost. 

Download Datasheet

High pressure STC-TCS Conversion Technology

To ensure a closed-loop polysilicon production, STC, generated in the CVD process as a by-product, should be reconverted to TCS. The conversion of STC to TCS is realized in the high pressure converter. SiTec's converters cause very low capital and operating costs due to high throughput, low energy consumption and high conversion efficiency.

Download Datasheet

Vent Gas Recovery (VGR) System

The VGR system separates vent gases coming from deposition and conversion processes for their constituents to be recovered and reintroduced into different steps of polysilicon production process. The SiTec VGR system enables a closed-loop polysilicon production and provides the highest recovery rates (>99%) for all vent gas components. The activated carbon adsorption system ensures high purification of recovered hydrogen.

Download Datasheet

Off Gas Treatment

To support the "green" polysilicon production, SiTec offers an additional Off Gas Recovery System including an optional HCl Recovery. It reduces the total HCl consumption in the polysilicon plant and respectively the salt load of the waste water so that even very strict salt limitations can be matched.

Filament Production

Silicon slim rods connected via bridges to silicon pairs serve as substrates for polysilicon deposition. The filament quality directly impacts the final polysilicon quality and is essential for a smooth start of the deposition process. SiTec offers a complete technology package including production, cleaning, handling and mounting of filaments.

Advanced Post Processing

The SiTec design of polysilicon post processing achieves high quality standards, secured by high degree of automation for transfer of polysilicon from the CVD reactor to finished polysilicon for sale. We offer post processing solutions for:

  • both solar grade and microelectronic grade polysilicon
  • variable automation degree (automated or manual breaking, classification, transport, packing of polysilicon; material tracking and storage systems)

Quality control, laboratory and online analytics, laboratory design

Continuous quality control is essential during the manufacturing of solar and microelectronic grade polysilicon. The SiTec quality control concept ensures continuous measurement at the specific process steps online and offline for feed materials, gases and liquids and the final product of polysilicon.

The process analytical package includes following analysis techniques:

  • Gas Chromatography (GC)
  • ICP-MS
  • Low temperature FTIR
  • Physical methods eg. life time, resistivity
  • Online analytical systems
  • LAB CVD reactor

Lab CVD Reactors for Chlorosilanes and Monosilane

Lab CVD Reactor (Laboratory Chemical Vapour Deposition Reactor) is proprietary equipment developed by SiTec. It is an essential part of the polysilicon production cycle and is used for quality assurance of process gases (TCS, STC, SiH4)

Download Datasheet Lab CVD Reactor for Chlorosilanes

Download Datasheet Lab CVD Reactor for Monosilane

DCS (Distributed Control System) including Application Software, FAT (Factory Acceptance Test), SAT (Site Acceptance Test) Commissioning

The application software is based on standard DCS function block library for chemical plants. Due to this open and tested structure it is easy to incorporate the whole poly plant including the utilities in a totally integrated system architecture. The CVD Reactor is controlled by customized function blocks containing our know-how, which ensures the most excellent product quality (depending on customer requirements). For optimum performance and best product quality the power supply unit for the CVD Reactor (MVI and MPC [Multistep Power Cabinet]) is fully integrated in the software architecture.