Indo-European Workshop on Solar Energy

Manufacture of Polysilicon in India – the Need and the Strategy

A Presentation by

Neeraj SinhaOffice of the Principal Scientific Adviser

to the Government of IndiaNew Delhi

21st / 22nd of April, 2010Indian Institute of Technology Jodhpur

Jodhpur, Rajasthan

Structure of the Presentation

• The Need

• The Technology

• The Initiative of the Office of the Principal Scientific Adviser to the Government of India (PSA’s Office)

• The Strategy

The Need

• Single crystals of silicon are of national importance, having strategic and commercial implications.

• Silicon technology has become a measure of the intellectual and industrialization level of any country. It is time for India to initiate an aggressive plan for the manufacture of poly and single crystals of silicon (required by foundries) to produce:

(i) Solar cells (ii) Microelectronics and power devices (iii) Photo detectors for industrial computer tomography, medical imaging, baggage scanning, etc. (iv) ICs for automation, process control, etc. (v) Nuclear radiation detectors• India does not produce single crystals of silicon, or even the

raw material needed to grow these – i.e. polysilicon. The industry is totally dependent on imports.

Integrated Programme on Si Technology Development

Company Country 2006 Production Capacity (Metric Ton)

Technology in use

Hemlock Semiconductors

USA 10,000 Siemens

Wacker Chemie Germany 6,500 Siemens / FBR

REC corporation Norway 6,000 Siemens / FBR

Tokuyama Japan 5,700 Siemens

MEMC USA 4,200 FBR / Siemens

Mitsubishi Japan 3,000 Siemens

Sumitomo Japan 900 Siemens

Others 3,200

Total 39,500

Worldwide technology-wise Polysilicon Production

(Source: Report of the Working Group on Polysilicon)

Availability of Polysilicon in the World Market

• Until about a year ago, there was a big crunch in the world market, with Indian cell and module manufacturing companies having to wait 1-2 years to get supplies of ingots and / or wafers. Assuming that 50% of the target of 20 GW of solar power by the year 2022 is to be achieved though the SPV route, the corresponding requirement of polysilicon would be about 1,00,000 tonnes in the next 12 years.

• Now, the situation has eased considerably, what with China having added multi-fold to its polysilicon manufacturing capacity during the past 1-2 years. Imports have, consequently, become much easier.

• But can we rely on just imports to meet the targets laid down in the Jawaharlal Nehru Solar Mission? Don’t we need to build indigenous capabilities?

• While prices have eased of late, what is the guarantee that both availability and prices of polysilicon will remain stable in the world market for the next say, 10 years?

Availability of Polysilicon in the World Market

• Furthermore, polysilicon manufacturing technology – especially the “Siemens process” – although available for purchase by prospective Indian manufacturers, is very costly. There is, therefore, a strong case for the setting-up of not one, but several polysilicon manufacturing units in India of capacities ranging from 2500 TPA to 5000 TPA and above.

• The only 2 polysilicon manufacturing units in India are of capacities 40 TPA and 100 TPA. While those efforts were commendable at an experimental level, they are, in no way, anywhere near sufficing the country’s needs.

• There has been a noteworthy effort in the private sector, by the LANCO Solar Private Limited, Hyderabad, for the setting-up of a 1250 TPA polysilicon manufacturing unit in Cuttack (Orissa) in phase-I with technology partnership from the USA and Europe.

• The plant is designed to produce ultra-high purity microelectronic grade silicon with crystal growth facilities for single crystals as well as multi-crystalline ingots and state-of-the-art wafer capabilities. The plant design and planning is expandable to 3500 TPA.

• The project has achieved financial closure and has received most of the requisite clearances.

• This may be the first large scale polysilicon facility coming up in India.

A Current Effort

The Technology

Czochralski process

• A method of crystal growth used to obtain single crystals of semiconductors (e.g. silicon, germanium and gallium arsenide), metals (e.g. palladium, platinum, silver, gold), salts, and synthetic gemstones. The process is named after the Polish scientist Jan Czochralski, who discovered the method in 1916 while investigating the crystallization rates of metals.

• The most important application is the growth of large cylindrical ingots, or boules, of single crystal silicon.

Bridgman technique

• It is a method of growing single crystal ingots or boules.

• It is a popular method of producing certain semiconductor crystals, such as gallium arsenide, where the Czocharalski process is more difficult.

Float-zone silicon

• A high-purity alternative to silicon grown by the Czochralski process. The concentrations of light impurities, such as carbon and oxygen, are extremely low. Another light impurity, nitrogen, helps to control microdefects and also brings about an improvement in mechanical strength of the wafers, and is now being intentionally added during the growth stages.

• Float-zone silicon is typically used for powers devices and detector applications. It is highly transparent to terahertz radiation, and is usually used to fabricate optical components, such as lenses and windows, for terahertz applications.

The Initiative of the PSA’s Office

• To take stock of the situation, a brainstorming session was held in the PSA’s Office on the 4th of August, 2006, with attendance from both the academia and the industry.

• The organizations that had participated in that session included

(i) The Bhabha Atomic Research Centre, Mumbai. (ii) The National Physical Laboratory, Council of Scientific and Industrial Research, New Delhi. (iii) The Bharat Electronics Limited, Bangalore. (iv) The Ministry of New and Renewable Energy, New Delhi.

(v) The Solid State Physics Laboratory, Defence Research and Development Organization, Delhi. (vi) The University of Mysore. (vii) The University of Delhi. (viii) The TATA Advanced Materials Limited, Bangalore.

• The participants were requested to prepare a position paper on Semi-conductor Crystals (in particular, silicon), to be discussed in a special session on the 13th of October, 2006 in the National Conference on Advances in Technologically Important Crystals, held in the University of Delhi, Delhi.

• That position paper formed the basis for the recommendations made on “Polysilicon” in the Report of the Working Group on R & D for the Energy Sector for the formulation of the Eleventh Plan (2007-2012).

• That Report had recommended the setting up of a facility for the production of: 2500 tonnes per annum (TPA) polysilicon, Growth of silicon single crystals of diameters upto 8",

and Characterization of poly, single crystals and finished

wafers.• The requirement of funds for the setting up of such a facility had been projected as about Rs. 1200 crores in that Report.

• A meeting to help operationalize the recommendation contained in the Working Group’s Report had, accordingly, been convened by the PSA’s Office on the 20th of March, 2007. The following decisions were taken:-

i) A Working Group chaired by the Chairman and Managing Director, Bharat Electronics Limited, Bangalore (or his nominee) would write a report and submit it to the PSA's Office giving the cost estimates and the approach to be adopted for the setting-up of the country's first 2500 TPA capacity polysilicon manufacturing facility.

ii) For obvious advantages of cheap and skilled manpower, low cost of raw material, etc., it would be better to locate the proposed polysilicon manufacturing facility in India, rather than abroad. With some efforts, and also with the cooperation of power utilities, it would definitely be possible to make available cheap and good quality uninterrupted electricity needed by the proposed facility.

iii) The Working Group would also suggest the best location in India for the setting-up of the proposed facility. The report would also bring-out the financial contribution that the various involved stakeholders would make for the purpose. Once the report of the Working Group was available, the involved stakeholders would work-out a business model for setting up a manufacturing plant.

• The Working Group submitted, in December, 2008, its report to the PSA’s Office.

• The feasibility report prepared by the Working Group requires a business model to be first put in place for equity participation by a myriad set of public and private sector companies. Hence the delay in operationalizing the recommendations contained in that report.

The Strategy

• Polysilicon manufacturing is highly capital and power intensive. Typically, the financing cost is about 50% of the total cost of production, while power contributes another 30%.

• Polysilicon production in India has to be price competitive against the landed cost of polysilicon in the country from large international players in the USA, Europe and China during the initial years, to establish its sustenance and economic viability.

• The cost of debt in India at ~12% is much higher than that prevalent in the USA, Europe and China.

• The Jawaharlal Nehru Solar Mission document recommends low interest rate loans and priority sector lending for manufacturing to achieve the installed capacity targets.

• We, therefore, need to facilitate low interest rate loans – as priority sector lending – through financial institutions to sustain and encourage the indigenous production of the strategic

polysilicon material.

THANK YOU for your kind attention