GaAs/AlGaAs/GaAs epi wafer

GaAs/AlGaAs/GaAs epi wafer

GaAs / AlGaAs / GaAs epi wafer in the diameter of 2” or 4” is available. This GaAs epitaxial wafer is applicable for semiconductor microwave devices and microwave monolithic integrated circuits. Here comes the typical structure of gallium arsenide epi wafer, please see below:

GaAs epi wafer

1. GaAs Wafer Epitaxial Structures

Structure 1:

2”GaAs/AlGaAs/GaAs epi wafer

S.No Parameters Specifications
1 GaAs substrate layer thickness 500μm
2 layer thickness 2μm
3 GaAs top layer thickness 220 nm
4 Mole fraction of Al (x) 0.7
5 Doping level Intrinsic

 

Structure 2:

2DEG GaAs/AlGaAs epi wafer (PAM-190224-GAAS-EPI)

Structure Composition Thickness(nm)
Cap GaAs 10
Doping carrier Al0.28GaAs1-0.28:Si 1.4×1018cm-3
spacer Alo.28GaAs1-0.28
channel GaAs
SL GaAs/Al0.28GaAs1-0.28 24A×24A
buffer GaAs 90
Sub SI GaAs(100)

 

Structure 3:

PAM181206-GAG

Layer Structure Composition Thickness
Mesa GaAs:Si
AlGaAs:Si 55nm
AlGaAs
GaAs 110nm
Beam GaAs
GaAs/AlGaAs SL
Sacrificial Layer AlGaAs
Substrate GaAs

 

Structure 4:

4″diameter AlGaAs/GaAs Wafer
The structure (top to bottom) PAM-190605-ALGAAS:
GaAs (10 nm)
AlGaAs (30 nm) with 30% Al and 70% Ga, doped at 1E18 cm^-3
Undoped AlGaAs (15 nm) (30% Al and 70% Ga)
GaAs (500 nm)
GaAs substrate

Remark: mobility and 2DEG concentration can be tested if necessary

Structure 5:

GaAs/AlGaAs epi stack wafers PAM-190711-ALGAAS
150nm of GaAs layer Standard error 3%
5um Al0.8Ga0.2As layer
2” GaAs substrate (backside polished)~ 330um

Expanation: the epi stack grows on top of GaAs substrate and contains 5 um of Al0.8Ga0.2As sacrificial layer and 150nm of GaAs layer on top of the sacrificial layer for the MBE-grown wafers.

2. GaAs Epi Wafer Industrial Standard Requirements

This standards specify the grades, requirements, quality assurance regulations and delivery preparations for semiconductor microwave devices and gallium arsenide epitaxial wafers for microwave monolithic integrated circuits.

2.1 Parameters of Epi Wafer of GaAs

The GaAs epitaxial technical parameters should meet the requirements of Table 1;

The GaAs epi wafer dimensions are conform with the requirements in the Figure 1 and Table 2.

GaAs epi wafer dimensions

Table 1 Technical Parameters of GaAs Epiwafer

Applications Microwave Monolithic Integrated Circuit Microwave Field Effect Transistor Microwave Diode
Power Low noise Power Low noise Beam lead mixer Schottky Barrier Tube Power Schottky Barrier Tube Gunn tube Varactor Hypermutation junction varactor
Epitaxial Wafer Structure Epitaxial layer (3) n+ n+ n+1) n+1) n+
Epitaxial layer (2) n n n n n n n
Epitaxial layer (1) n- n- n- n- n+ n+ n n+ n △n
Substrate S.I S.I S.I S.I n++ n++ n++ n++ n++
Epitaxial Layer (3) Carrier concentration (cm-3) ≥1 x 10 18 ≥1 x 10 18 ≥1 x 10 18
Thickness (um) 0.1~0.4
Mobility at Room Temperature (cm2/V.s)
(2) Carrier concentration (cm-3) 1.5 x 1017~2 x 1017 2 x 1017~2.5 x 1017 5 x 1016~2 x 1017 1.0 x 1017~3 x 1017 8 x 1015~2 x 1017 4 x 1014~1.5 x 1016
Thickness (um) 0.2~0.5 0.2~0.5 0.2~0.4 0.3~0.5 30~1.5
Mobility at Room Temperature (cm2/V.s) >3000 >3000 >3000 >3000 7000~4000
(1) Carrier concentration (cm-3) <1 x 1014 <1 x 1014 ≥1 x 1018 ≥1 x 1018 5 x 1014~1 x 1016 ≥5 x 1017 4 x 1015~10 x 1015 5 x 1015~5 x 1016
Thickness (um) 3~5 3~7 3~50 2~4 2~6 1~4
Mobility at Room Temperature (cm2/V.s)
Substrate Carrier concentration (cm-3) ≥1 x 1018
Resistivity(ohm-cm) ≥1 x 107
Thickness (um) See table 2
Mobility at Room Temperature (cm2/V.s) >1800 >2200
Orientation (100)
Growth Method LEC, HB LEC, HB LEC, HB LEC, HB LEC, HB LEC, HB HB HB


Mark:

* Substrate dopants are negotiated by the demander and the supplier;

* When deviating, deviate 2°±0.5° to the nearest (110) direction.

Table 2 GaAs Epitaxy Dimensions

Parameters l h A B D OF IF Thickness Smin
mm um cm2
Rectangle ≥10 ≥10 350~650 1.0
≥15 ≥10 1.5
D Shape 51~56 40~47 350~650 18.0
63~68 50~56 27.5
Round Shape 40 ± 1 12.5±1 7 ± 1 350~650 12.5
50 ± 1 16±1 7 ± 1 19.5
76 ± 1 22±1 12 ± 1 550~650 45.3
100 ± 1 32.5 ± 1 18 ± 1 600~650 78.5

 

Mark:

Smin represents the area of the epitaxial wafer of GaAs.

2.2 AlGaAs / GaAs Quantum Structure Wafer Quality

Concentration Uniformity of GaAs Epi Wafers:

The concentration uniformity of the active layer of the GaAs epitaxial wafer should be less than or equal to 10%;

The thickness uniformity of the Iactive layer should be less than or equal to 10%;

The the active layer thickness of GaAs wafer should be less than or equal to 10%.

GaAs Wafer Transition Zone Width:

The width of the transition zone of the indium gallium arsenide epitaxial wafer buffer layer for field effect transistors should not be greater than 0.90umc.

GaAs Epi Wafer Surface quality:

* There should be no contamination on the surface of the AlGaAs / GaAs epitaxial wafer;

* There should be no fog, pitting, scratches, scratches on the GaAs epi wafer on GaAs substrate surface;

* The GaAs epitaxy surface should be smooth and bright;

* If there are special requirements for the surface quality of the GaAs wafer on GaAs film, it should be negotiated by the supplier and the buyer.

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

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