PBN Products

Fri, 29 Feb 2008 16:26:32 -0800

PBN Crucibles for VGF

Available from 2" in diameter to 6" in diameter

Height from 7" to 10"

PBN Crucibles for LEC

Available from 3" in diameter to 8" in diameter

n- and p-type Ge

Fri, 29 Feb 2008 16:25:03 -0800

Semi-conducting Ge Specifications

Growth Method	VGF
Dopant	n-type: As; p-type: Ga
Wafer Shape	Round (DIA: 2" TO 6")
Surface Orientation**	(100)±0.5°

**Other Orientations maybe available upon request

Gallium Metal

Fri, 29 Feb 2008 16:22:08 -0800

Purity Levels
4N	6N	7N	MBE Grade - 8N
99.99%	99.9999%	99.99999%	99.999999% Plus

Total Impurities
<50ppm	<500ppb	<50ppb	<10ppb

Critical Elements
Cu	<10ppm	<0.5ppb	<0.5ppb	<0.5ppb
Zn	<5ppm	<3.0ppb	<1.0ppb	<1.0ppb
Cd	<5ppm	<0.5ppb	<0.5ppb	<0.5ppb
Si	<2ppm	<1.0ppb	<0.5ppb	<0.5ppb
Fe	<5ppm	<0.1ppb	<0.1ppb	<0.1ppb
Al	<5ppm	<0.2ppb	<0.2ppb	<0.2ppb
Ca	<5ppm	<5ppb	<5.0ppb	<5.0ppb
Na	<5ppm	<0.2ppb	<0.2ppb	<0.2ppb
Pb	<10ppm	<0.5ppb	<0.5ppb	<0.5ppb
In	<10ppm	<1.0ppb	<0.5ppb	<0.5ppb

Analysis Method: Glow Discharge Mass Spectroscopy (GDMS)

Undoped GaAs

Fri, 29 Feb 2008 16:20:49 -0800

Semi-Insulating GaAs Specifications

Growth Method	VGF
Dopant	Carbon
Wafer Shape*	Round (DIA: 2", 3", 4", and 6")
Surface Orientation**	(100)±0.5°

*5" Wafers available upon request

n- and p-type GaAs

Fri, 29 Feb 2008 16:16:51 -0800

Semi-conducting GaAs Specifications

Growth Method	VGF
Dopant	Si (n-type) AND Zn (p-type)
Wafer Shape	Round (DIA: 2", 3", 4" and 6")
Surface Orientation*	(100)±0.5°

*Other Orientations maybe available upon request

n- and p-type InP

Fri, 29 Feb 2008 16:11:57 -0800

Semi-conducting InP Specifications

Growth Method	VGF
Dopant	n-type: S, Sn AND Undoped; p-type: Zn
Wafer Shape	Round (DIA: 2", 3", AND 4")
Surface Orientation	(100)±0.5°

*Other Orientations maybe available upon request

Fe Doped InP

Fri, 29 Feb 2008 12:10:28 -0800

Semi-Insulating InP Specifications

Growth Method	VGF
Dopant	Iron (FE)
Wafer Shape	Round (DIA: 2", 3", AND 4")
Surface Orientation	(100)±0.5°

*Other Orientations maybe available upon request

Product Specifications

Fri, 15 Feb 2008 10:56:00 -0800

Raw Material
--	PBN
--	Gallium Metal

GaAs Substrates
--	GaAs SI
--	GaAs SC

InP Substrates
--	InP SI
--	InP SC

Ge Substrates

AXT Request For Quote

Thu, 09 Feb 2006 14:05:48 -0800

Thank you for inquiring about our products. Expect to hear from us soon!

Packaging and Delivery

Wed, 08 Feb 2006 18:47:35 -0800

After manufacturing, we individually inspect all substrates, measuring their flatness, bow and taper, and checking them for surface saw marks, edge chips and cracks. We then package them in a class 100 environment and ship them to customers in inert-atmosphere individually-sealed containers to secure the substrate quality at delivery.

In order to satisfy customers' just-in-time delivery requirements, we generally keep a consignment supply of as-sliced substrates in inventory for our standard product lines. In most cases, our customers can expect a quick turnaround in 2 to 4 weeks.

Quality Control

Wed, 08 Feb 2006 18:46:24 -0800

At AXT, we are committed to quality in every step of our manufacturing sequence. To ensure our products' quality, we use state-of-the-art, highly automated equipment and perform extensive quality control in every processing step. For instance, we employ a computerized Van der Pauw system to measure resistivity, conduction type, carrier concentration, and the Hall mobility. In addition, we use infrared transmission to monitor lattice defects, impurities and internal stress. We also apply sophisticated characterization techniques to track product quality, such as photoluminescence and X-Ray diffraction, to monitor the impurity distribution and crystal orientation, respectively. In addition, we are in the process of installing a Total Reflection X-Ray Fluorescence (TXRF) system for monitoring and controlling surface trace metals on our substrates.

Joint Venture Operations in China

Wed, 08 Feb 2006 18:31:39 -0800

As the raw materials required by our compound semiconductor substrates play such an essential role in our growth and reproducibility, we participate in joint ventures with five Chinese companies. Through them, we manufacture and sell critical materials and parts listed in the products overview. This arrangement reduces our dependency on other suppliers of raw materials, plus it affords us price and volume stability unavailable to those purchasing on the open market. In addition, AXT is a majority owner in three of the key ventures, which affords us board-level control.

The five joint ventures are:

Product Features

Wed, 08 Feb 2006 18:29:26 -0800

A direct consequence of the relatively low defect density in VGF grown GaAs substrates is the increased mechanical strength of the material. Substrates with a high dislocation density can easily form microcracks where the dislocations coalesce. An almost linear increase in wafer fracture strength, with decreasing dislocation density, has been observed. High mechanical strength is desirable, because it results in reduced wafer breakage during volume processing. It also allows the use of thin wafers during processing, eliminating the thinning steps often required for devices. The superior mechanical properties of GaAs VGF grown substrates lead to a unique AXT feature - extra thin 100µm-thick wafers.

The relationship of structural imperfections of epitaxial layers to their substrates has been closely examined by Bassignana and Macquistan¹. Layers of 2-µm thick Al.5Ga.5As were grown by conventional molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) on LEC GaAs semi-insulating substrates. Studies showed that all the threading dislocations associated with the dislocation cellular network in the substrate extend up into the epitaxial layer in exact one-to-one correspondence. This dislocation propagation exists in both MBE and MOCVD growth. Hence, a higher quality substrate is a primary condition for obtaining a high quality epilayer.

Although the dislocation density of the substrates has been shown to strongly affect the quality of epitaxial layers, a common claim is that it has no definite effect on the device's performance. Decisive effect on device performance has been found to be related to AB defects², although the origin of AB defects is not well understood. These defects can be revealed by AB solution etching as oval defects, and are generally believed to be As precipitates. Field-effect transistors (FETs) with more AB defects exhibit poorer performance and uniformity. In VGF grown GaAs substrates, the AB defect density may be orders of magnitude lower than in GaAs substrates grown using the LEC technique, and therefore such VGF grown GaAs substrates are more suitable for these epitaxial devices.

Product Line

Wed, 08 Feb 2006 18:28:07 -0800

AXT's products include both high-performance semiconductor substrates for major electronic and opto-electronic applications, and a line of industry-critical raw materials.

In substrates, our main product line consists of gallium arsenide (GaAs) substrates in two-, three-, four-, five-, and six-inch diameters. We offer a second product line of indium phosphide (InP) substrates in two-, three-, and four-inch diameters. We also produce single-element substrates manufactured from germanium (Ge) in two- and four-inch diameters. We produce our wafers at our Tongmei facility, located in a suburb of Beijing. This large manufacturing complex totals eight buildings with about 190,000 square feet of factory area, making it what we believe is the world's largest III-V wafer production facility.

AXT Inc. - Products

PBN Products

n- and p-type Ge

Gallium Metal

Undoped GaAs

n- and p-type GaAs

n- and p-type InP

Fe Doped InP

Product Specifications

AXT Request For Quote

Packaging and Delivery

Quality Control

Joint Venture Operations in China

Product Features

Product Line