News

DTI developes new process to high purity InP(Indium Phosphide) Substrates Manufacturing

  Introduction of DTI
Operation —Products: stainless steel fittings, tubings, high purity tubes, valves, filters, heat exchangers, vacuum components, bellows, vacuum flexible hose, BPE fitting/valve, B.A./E.P. tube/pipe. —Customer: globe sales agent network  Taiwan: Episil Technology Inc., Formosa Petrochemical Co., Development Center for Biotechnology, etc. world wide: USA, Canada, Germany and Singapore. —Staff: 18 —Turnover: U$ 1 million (2009) —Finance: no liability liquidity U$ 1.2 million credit U$ 0.23 million —Capital increase: fixed assets will up to U$ 3.1 million in 2 years

Product Development

1. 2 and 3 inch S-doped/ n-type semiconductor InP single crystal
2. VGF growth system

• high temperature and high pressure

      single crystal growth furnace

• single crystal growth control system

 

2. Advantage of InP based device

• excited wavelength match to the fiber communication (1310 ~ 1550 nm)
• high electron mobility
• high thermal conductivity
• low power loss
• low noise

Market Status     
Applicaiton and development of InP based device

1. Optical fiber communication

• global cable laying =  earth/moon distance x 8;  15 % increase/year (ref. Corning)
• urban development of FTTx; by Verizon/AT&T; @ Level 3
• long haul DWDM by fiber communication increasing: 10 Gbs →40 Gbs→160 Gbs

2. Optoelectronic integration circuit

• For a faster transmission and enhanced system function, Optical-to-Optical (OEO) conversion costs of the data transmission can not be ignored as the increased of discrete components.
• cost considerations force the fiber communications components shift from a discrete component to a photonic integrated circuits (PIC)
• InP photonic integrated circuits, in recent years, getting breakthrough in the optical communications as the electronic integrated circuit technology development of Si.

3.Millimeter wave in military communication

• Technology for frequency agile digitally synthesized transmitters program (DARPA, 2003), demanding the development of transistors with cut-off frequencies of up 500 GHz.
• Sub-millimeter wave imaging focal plane technology (DARPA, 2006), building an imaging system operating at 340 GHz.
• Terahertz electronics program (DARPA, 2009); Phase I: 670 GHz, Phase II: 850 GHz, Phase III: 1030 GHz.

  InP based optoelectronic device industry
  Table. Turnover of InP device industry in USA, 2009’  (U$)
 

Company	Epitaxy	Device	Total Sales Revenue (U$ M)	InP Chip Sales Revenue Related Among Total  (U$ M)
JDS Uniphase	Yes	Yes	1,200	480
Finisar	Yes	Yes	550	250
Infinera	Yes	Yes	308	280
CyOptics	Yes	Yes	280	250
Oclaro	Yes	Yes	286	115
Avago	Yes	Yes	1,570	390
Opnex	Yes	Yes	326	130

Ps.                               (total U$ 4,520 M  total U$ 1,895 M)
1)Turnover from the number of public information
2)Optical communication company chosen in USA

• More than 150 InP based optoelectronic components manufacturers and research institutes
• InP based optoelectronic device market status
  ♦ sales of InP based laser and photodetectors > US$2.0 B
  ♦ market size of InP based optoelectronic device > US$5.0 B
  ♦ Similar to the GaAs, InP based optoelectronic device has grown and being mature for decades study.
  ♦ Production cost —most important factor: lack of cheap/good InP wafer

  InP wafer industry status
  Only 5 global manufacturers of InP wafers
  

USA	AXT Inc.,  Crystacomm Inc.
Japan	Nikko Materials, Sumitomo Electric
France	InPact

  Nearly 80 % of the wafer supplied by Japan, and the price is expensive.

  Single crystal grown by various technologies
 

Features/ Technology	VGF	LEC	VCZ
Material purity control	excellent	acceptable	good
Stoichiometric control	excellent	hard	good
Dislocation density	103/cm2	105/cm2	103/cm2
Thermal stress	low	high	medium
Dopant control	good	hard	acceptable
Uniformity &  consistency	excellent	hard	acceptable
Crystal diameter control	easy	hard	hard
Labor cost	low	medium	high
Equipment costs	low	medium	high
Yield	medium	high	high
Crystal length	medium	long	medium
Automation	good	poor	poor

  Simultaneous Synthesis and VGF growth

  • Cornerstone 
     ♦ key technology: VGF 
     ♦ Advantage of VGF: crystal quality & yield
• Objective
     ♦ more streamlined steps —cost down: time, equipment, space, labor…     
     ♦ competitiveness: lower price product 
• Difficulty 
     ♦ hardware: heating element, crucible supporting design, high pressure gas flow control, temperature gradient… 
     ♦ urgency: funds…
• Superiority: an expert in VGF
 
Comparison of InP single crystals fabricated by DTI and others

 

 

 

Characteristics / Manufactures	DingTen (Taiwan)	AXT (US)	Sumitomo (Japan)	InPact (France)
Growth method	SS-VGF	VGF	VCZ	LEC
Dopant	sulfur	sulfur	sulfur	sulfur
Carrier concentration ( x 1018 cm-3)	~ 1.7	0.8 ~ 8	2 ~ 8	3 ~ 10
Mobility (cm2V-1s-1)	1,400	1,000 ~ 2,500	1,000 ~ 2,000	1,300 ~1,600
Etching pit density (cm-2)	< 4,000	100 ~ 5,000	500 ~ 5,000	100,000
Crystal diameter (inch)	2	2 & 3	2, 3 & 4	2 & 3

  Main task in this project

• High temperature/high pressure furnace development
• Multiple heating system
• Crucible and supporting desing
• Thermal simulation and temperature gradient
• Crystal quality analysis
• Optoelectronic characteristics analysis
• Crystal quality control —Process optimization of 2” S-doped InP single crystal
• Process optimization of 3” S-doped InP single crystal

  Technical Specifications

  (I) InP single crystal
  Table . Technical specifications evolution of InP single crystal through this project

Specifications	Before (2009’)	After (2012’ Q1)
Single crystal diameter (inch)	2	2、3
Crystal type	S-doped, n-type semiconductor	S-doped, n-type semiconductor
Orientation	(100)±0.5o	(100)±0.5o
Carrier concentration (cm-3)	1.7 ´1018	2 ~ 8 ´1018
Resistivity (ohm-cm)	1.9 ´10-3	0.6 ~ 2.5  ´10-3
Electron mobility (cm2V-1SS-1)	1,900	1,000 ~ 2,000
Etching pit density (cm-2)	~ 4,000	£ 500
Yield (%)	20	50
Ingot length (inch)	1	2
Crystal growth rate (mm/h)	2 ~ 3	5

  (II) high temperature/high pressure furnace
  Table . Technical specifications evolution of high temperature/             high pressure furnace through this project
 

Specifications	Before (2009’)	After (2012’ Q1)
Pressure tank - materials	SA106B stainless steel	SA106B stainless steel
diameter (mm)	200	300
thickness of plate (mm)	15	20
max. pressure (atm)	75	100
Heating element	1 or 4	6
heater diameter (mm)	70	90
refractory	Al2O3	Z-type fiber Al2O3
max. temperature (oC)	1,500	1,600
Max. working temperature (oC)	1,300	1,400

  Competitive Analysis

Advantage of SS-VGF ® DTI
• reduce the InP single crystal growth process; diminish the facilities, space, and operator; cost down
♦ get high quality and low-cost products
♦ Hardware R&D
♦ high temperature/high pressure tank 
• R&D capability – teamwork of materials science and engineering, electrical and electronics, mechanical engineering
♦high temperature/high pressure furnace – General manager Rudy
• InP single crystal growth – Dr. Hu
♦analysis and QC – Mr. Jason, Dr. Chen
♦factory – Mr. Tsai