Indium Antimonide (InSb) Single Crystal Substrates

Indium Antimonide (InSb) Single Crystal Substrates

Xiamen Powerway Advanced Material Co., Ltd (PAM-XIAMEN) offers InSb crystal wafer up to 2″ in diameter that are grown by a modified Czochralski method from highly purified, zone refined polycrystalline ingots. More about the indium antimonide crystal substrate specifications, please see the following part:

indium antimonide wafer

1. Indium Antimonide Wafer Specifications

No 1. 2″ InSb Wafer

No 2. 2″ InSb Substrate
Carrier Concentration: 0.8 – 2.1 x 1015 cm-3
Thickness:450+/- 25 um; 525±25µm
EPD < 200 cm-2

No 3. 2″ InSb Thin Film
Orientation:(111) + 0.5°
Thickness:450+/- 50 um
Carrier Concentration: < 5 x 1014 cm-3
EPD < 5 x 103 cm-2
Surface roughness: < 15 A
Bow/Warp: < 30 um

No. 4 Indium Antimonide Substrate 2 Inch
Orientation:(111) + 0.5°

No. 5 Indium Antimonide Wafer 50.8 mm
Ro=(0.020-0.028) Ohm-cm,
One side edge;
In(A) Face: Chemically-mechanically final polished to 0.1µm (Final Polish),
Sb(B) Face: Chemically-mechanically final polished to <5µm (Laser mark),
NOTE: Nc and Mobility are at 77ºK.

Indium Antimonide (InSb) wafer can be offered as wafers with as-cut, etched or polished finishes with wide range of doping concentration and thickness. The wafer could be high quality epi-ready finishing.

2. Indium Antimonide Properties

Indium antimonide is silvery, brittle, and has a zinc blende structure. The indium antimonide constant is 6.48 Å, which is a direct band gap material with a narrow band gap of 0.18 eV. The electron mobility is as high as 7800 cm2/V·s. The melting point of indium antimonide is 525°C. Compared with other III-V group compounds, it is more easy to purify and grow single crystals. More basic properties please see the figure below:

InSb Properties

InSb Properties at 300K

Following diagram shows the indium antimonide carrier concentration and band structure at 300K:

InSb Band structure and carrier concentration

The InSb Electron Mobility is changes with the temperature:

InSb Electron Mobility Vs Temperature

3. Indium Antimonide Single Crystal Wafer Preparation

The InSb single crystal is prepared by the Czochralski method, and the raw material InSb is purified by zone melting. In InSb material, except for tellurium, the effective segregation coefficient is close to 1, and the effective segregation coefficient of other harmful impurities is less than or greater than 1. Meanwhile, the purity of indium antimonide substrates can be effectively improved.

The basic process of CZ growth is that the melt is kept in high-purity hydrogen or high-purity nitrogen containing high-purity H210%-20% at a constant temperature of about 800℃ for 0.5h, which can effectively remove scum on the surface of the melt. It grows significantly along the <111> direction, and the facet effect caused by the radial carrier distribution is very uneven. The growth is along with <100>, <115>, <113> and other crystal directions, and the facet effect can be eliminated. InSb, in addition to D pits, S pits (dish-shaped pits) and P pits (puching-out) are also observed. There are D pits, S pits (dish-shaped pits) and P pits (puching-out) in the indium antimonide thin films. The indium antimonide doped with isoelectronics (such as N doping) can reduce the density of these defects.

4. Challenge for InSb (111) Wafer Manufacturing

Due to the particularity of the indium antimonide material, the electrical parameters of the InSb wafer processed by the crystal grown in the <111> direction are poor, and cannot meet the needs of the focal plane device. Therefore, the InSb crystal must be grown in the <211> direction and then cut the crystal through the <111> direction to obtain the indium antimonide <111> wafer. Due to the anisotropic nature of the crystalline material, when growing a single crystal ingot in the <211> direction, the growth rate is different in each direction, so the growth interface is not approximately circular, but a “D” shape or trapezoid.

The difference in the growth interface eventually leads to different shapes of the two indium antimonide ingots grown in different directions. The equal-diameter part of the ingot grown in the <111> direction is similar to a cylinder. The equal-diameter part of the ingot grown in the <211> direction is similar to a dam. Such ingots grown in the <211> direction need to be rotated at a certain angle when cutting in the <111> direction. Since the rotation direction is perpendicular to the large surface, the height of the trapezoid can be increased to a certain extent, thereby reducing the height ratio of the bottom side. This increase in height still has a considerable difference in size from the large base, and the height is often only half the size of the base. This kind of irregularity is a huge challenge for the standardized process of indium antimonide wafers.

5. InSb Single Crystal Wafer Applications

Epi-ready single crystal InSb substrate with surafce roughness less than 0.5 nm is suitable for molecular beam epitaxy (MBE) growth. At the same time, because Indium antimonide conduction electron is high, InSb is a good substrate material for infrared detectors, Hall devices, and magnetoresistive devices.

For example, imaging devices and indium antimonide focal plane array devices corresponding to the 3 to 5 μm band of the atmospheric transmission window. In addition, in charge injection devices, the number of InSb devices has reached 128×128 arrays. The hybrid focal plane array composed of 3~5μm waveband InSb photovoltaic detectors as sensitive elements has also been greatly developed, and it has been made into a two-dimensional array with a large number of elements.

Except for the InSb substrates, GaSb wafer in 2 inch also can be offered by PAM-XIAMMEN, take the below one for example:

2 Gallium Antimonide Substrate

Type/Dopant:P/undoped; N/undoped
Polish:SSP; DSP

Surface Condition and other Specification


For more information, please contact us email at [email protected] and [email protected].

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