A member of AMG Advanced Metallurgical Group, N.V.

A- A+

SCU – Silicon Crystallization Furnaces for Multi- and Mono-Crystalline Ingot Production

Technology and Quality Leadership

ALD Vacuum Technologies is the technology and quality leader company in the field of silicon ingot production for solar applications. We were first to introduce Generation 5, Generation 6 and 1000 kg furnaces. ALD has a long history of engineering and manufacturing the highest quality furnaces.

Multi-Crystalline silicon ingots are produced by crystallizing molten silicon in quartz crucibles. The key to improved multi-crystalline wafer product quality and high-throughput is constant-rate crystallization and vertical grain growth.   



The SCU design uses both top and bottom heaters to ensure: 

  • Uniform temperature profiles – flat solid/liquid interface prevents accumulation of inclusions that can lead to wire saw issues.
  • Vertical heat flux across crucible width – minimizes side-wall growth making higher quality side and corner bricks.
  • Shorter cycle times – high production rates are maintained with different crucible suppliers since the power supplies are independently controlled.  Customers are able to save production cost by having a wider choice among the possible crucible suppliers.
  • Easy to scale – the SCU450/650 can be ordered with your choice of current Gen 5 or the new Gen 6 hot zone to further reduce production costs.

Mono-Crystalline ingots are produced using ALD furnaces with additional options and Mono2 patented technology. This unique process technology was purchased from BP Solar in 2010 and was optimized for use in SCU furnaces. We provide the furnaces, technology transfer, training and a license to use our patented method.

Benefits for the wafer manufacturer producing Mono2™ wafers include:

  • Higher margins – mono wafers can be produced with high throughput and much lower manufacturing cost when compared with CZ pullers.
  • Better scrap utilization – unlike CZ pullers, the growth interface is protected from floating particulates; this enables the wafer producer to use more scrap material and lower their net silicon purchases.
  • Less floor space and maintenance – a 500MW wafer factory needs less than 60 Mono2™  furnaces compared with nearly 200 CZ pullers. 

Interested in more information?