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The polycrystalline ingot is obtained by a Horizontal Gradient Freeze (HGF) which is the cooling of an InP Melt obtained by reaction between liquid indium and phosphorus vapour at 30 atmospheres. This method produces high purity, stoechiometric Indium Phosphide. The ingot is 300 mm long and the section is half of a 45 mm diameter. Each ingot weighs 1 250 g.
InP single crystal
The tCZ growth (modified Czochralski method) is used to pull a single crystal through a boric oxide liquid encapsulant starting from a seed. The dopant (Fe, S, Sn or Zn) is added to the crucible along with the polycrystal. High pressure is applied inside the chamber to prevent decomposition of the Indium Phosphide. InPACT has developed a process to yield fully stoechiometric, high purity and low dislocation density InP single crystal.
The tCZ technique improves upon the LEC method thanks to a thermal baffle technology in connection with a numerical modeling of thermal growth conditions. tCZ is a cost-effective mature technology with high quality reproducibility from boule to boule.
Some comparative technical data :
InP Wafer processing
Each ingot is cut into wafers which are lapped, polished and surface prepared for epitaxy. The overall process is detailed hereunder.
Flat specification and identification The orientation is indicated on the wafers by two flats (long flat for orientation, small flat for identification). Usually the E.J. standard (European-Japanese) is used. The alternate flat configuration (U.S.) is mostly used for Ø 4" wafers.
Orientation of the boule Either exact (100) or misoriented wafers are offered.
Accuracy of the orientation of OF In response to the needs of the optoelectronic industry, InPACT offers wafers with excellent accuracy of the OF orientation : < 0.02 degrees. This feature is an important benefit to customers making edge-emitting lasers and also to manufacturers who cleave to separate dies – allowing their designers to reduce the “real-estate” wasted in the streets.
Edge profile There are two common specs : chemical edge processing or mechanical edge processing (with an edge grinder).
Polishing Wafers are polished by means of a chemical-mechanical process resulting in a flat, damage-free surface. InPACT provides both double-side polished and single-side polished (with lapped and etched back side) wafers.
Final surface preparation and packaging Wafers go through many chemical steps to remove the oxide produced during polishing and to create a clean surface with stable and uniform oxide layer that is ready for epitaxial growth - epiready surface and that reduces trace elements to extremely low levels (EPICLEAN ). After final inspection, the wafers are packaged in a way that maintains the surface cleanliness.
Specific instructions for oxide removal are available for all types of epitaxial technologies (MOCVD, MBE).
Database As part of our Statistical Process Control/Total Quality Management Program, extensive database recording the electrical and mechanical properties for every ingot as well as crystal quality and surface analysis of wafers are available. At each stage of fabrication, the product is inspected before passing to the next stage to maintain a high level of quality consistency from wafer to wafer and from boule to boule.
The polycrystalline ingot is obtained by a Horizontal Gradient Freeze (HGF) which is the cooling of an InP Melt obtained by reaction between liquid indium and phosphorus vapour at 30 atmospheres. This method produces high purity, stoechiometric Indium Phosphide. The ingot is 300 mm long and the section is half of a 45 mm diameter. Each ingot weighs 1 250 g.
InP single crystal
The tCZ growth (modified Czochralski method) is used to pull a single crystal through a boric oxide liquid encapsulant starting from a seed. The dopant (Fe, S, Sn or Zn) is added to the crucible along with the polycrystal. High pressure is applied inside the chamber to prevent decomposition of the Indium Phosphide. InPACT has developed a process to yield fully stoechiometric, high purity and low dislocation density InP single crystal.
The tCZ technique improves upon the LEC method thanks to a thermal baffle technology in connection with a numerical modeling of thermal growth conditions. tCZ is a cost-effective mature technology with high quality reproducibility from boule to boule.
Some comparative technical data :
InP Wafer processing
Each ingot is cut into wafers which are lapped, polished and surface prepared for epitaxy. The overall process is detailed hereunder.
Flat specification and identification The orientation is indicated on the wafers by two flats (long flat for orientation, small flat for identification). Usually the E.J. standard (European-Japanese) is used. The alternate flat configuration (U.S.) is mostly used for Ø 4" wafers.
Orientation of the boule Either exact (100) or misoriented wafers are offered.
Accuracy of the orientation of OF In response to the needs of the optoelectronic industry, InPACT offers wafers with excellent accuracy of the OF orientation : < 0.02 degrees. This feature is an important benefit to customers making edge-emitting lasers and also to manufacturers who cleave to separate dies – allowing their designers to reduce the “real-estate” wasted in the streets.
Edge profile There are two common specs : chemical edge processing or mechanical edge processing (with an edge grinder).
Polishing Wafers are polished by means of a chemical-mechanical process resulting in a flat, damage-free surface. InPACT provides both double-side polished and single-side polished (with lapped and etched back side) wafers.
Final surface preparation and packaging Wafers go through many chemical steps to remove the oxide produced during polishing and to create a clean surface with stable and uniform oxide layer that is ready for epitaxial growth - epiready surface and that reduces trace elements to extremely low levels (EPICLEAN ). After final inspection, the wafers are packaged in a way that maintains the surface cleanliness.
Specific instructions for oxide removal are available for all types of epitaxial technologies (MOCVD, MBE).
Database As part of our Statistical Process Control/Total Quality Management Program, extensive database recording the electrical and mechanical properties for every ingot as well as crystal quality and surface analysis of wafers are available. At each stage of fabrication, the product is inspected before passing to the next stage to maintain a high level of quality consistency from wafer to wafer and from boule to boule.
- The largest Western producer of Indium Phosphide substrates covering all dopants (Fe, Sn, Zn, S) and all diameters (2", 3", 4").
- Dedicated exclusively to InP, InPACT provides high-performance substrates for a wide range of devices for both micro (HBT, HEMT) and optoelectronic (LED, LD, PIN, APD).
- Founded in 1988, InPACT has an extensive manufacturing experience (18+ years) of InP.
- InPACT is an independent, private company owned by three founders and two Venture capitalists (Banexi Ventures from BNP Group and Innovacom from France Telecom Group).
- The plant is located in the French Alps, near the high tech Center of Grenoble. With the current design, it enables to triple production capacity within 6 months. A $10 million investment for a state-of-the-art crystal growth and wafer processing plant.
- InPACT serves 100+ customers worldwide. The customer profile includes leading telecom components producers, start-ups as well as leading Government Research Centers and Univ.
- Market share has increased to ~ 20% (merchant market), # 1 European/American producer.
- With its proprietary Epiready technology (EPICLEAN ), the company is strategically positioned to be a dominant supplier of InP substrates.
- EPICLEAN : lowest contamination before (on the substrate epi-ready surface) and after epitaxy (substrate-epilayer interface).
InPACT epiready recipe has been developed to control the contamination level. Unlike competing recipes, our cleanroom environment, our consumables and our chemistry are monitored with the TOF SIMS tool, to check in real time the level of contamination, thereby reducing the risk of trace elements during all the wafer processing steps.
EPICLEAN enables InPACT to produce substrates with superior epi-ready surface cleanliness which leads to purer substrate-epilayer interface by up to one order of magnitude as proven by a number of MOCVD and MBE groups.
- Mechanically cleaved (distinguished from natural cleave) major flat with accuracy up to 0.02°.
- Superflat surface with TTV< 3um and LTIR < 0.8 um.
- 4" diameter products with the support of the French Anvar and European organisations (Eureka, Eurimus) for HBTs and InGaAs detectors.
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