| HS Code | 538000 |
| Chemical Formula | GeH4 |
| Cas Number | 7782-65-2 |
| Purity | 99.999% |
| Grade | Electronic/EL |
| Appearance | colorless gas |
| Odor | pungent, garlic-like |
| Vapor Pressure 20 C Kpa | >101.3 |
| Solubility In Water | slightly soluble |
| Flammability | flammable gas |
| Toxicity | highly toxic |
| Hazard Class | 2.3 / 2.1 |
As an accredited Germane (GeH₄) Electronic/EL Grade factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Packaged in high-pressure carbon steel cylinders, typically 47 liters, with CGA 660 valve, containing 10 kg net. |
| Container Loading (20′ FCL) | 20' FCL: Cylinders, upright and secured in ventilated container, with separation, shock protection, and hazmat signage for toxic gas. |
| Shipping | Germane (GeH₄) Electronic/EL Grade is shipped as a liquefied, high-pressure gas in certified steel or specialty cylinders. It is a toxic, pyrophoric, and flammable hazard, requiring secure valve protection, leak-proof seals, and compliance with dangerous goods regulations. Transport must be upright, dry, and properly labeled to ensure safe handling. |
| Storage | Germane (GeH₄) Electronic/EL Grade is stored as a liquefied compressed gas in high-pressure steel or compatible alloy cylinders. Keep cylinders upright, secured, and in a cool, dry, well-ventilated area away from sunlight, heat, and ignition sources. Store separately from oxidizers, ensuring proper labeling, grounding, and continuous leak detection per hazardous gas regulations. |
| Shelf Life | Shelf life is typically 24 months when stored in a sealed cylinder at recommended temperatures, away from air and moisture. |
SiGe heterojunction bipolar transistor base layers use germane delivered as a 10 vol% mixture in hydrogen to a single-wafer reduced-pressure chemical vapor deposition reactor. The chamber is configured with a SiC-coated graphite susceptor, tungsten-halogen lamp arrays, and dual-wavelength pyrometry. A typical base deposition sequence runs at 550–650 °C and total pressure below 80 Torr, with silane, germane, methylsilane, diborane, and hydrogen chloride in the hydrogen carrier. The germane fraction in the hydride feed is adjusted between 0.5% and 2.0% to produce Ge contents of 15–30 at%. Carbon is co-deposited at 0.1–0.3 at% through methylsilane to suppress boron transient-enhanced diffusion. Diborane flow is set to achieve active boron concentrations from 5×10¹⁹ cm⁻³ to 1×10²⁰ cm⁻³. Selective growth on patterned oxide is maintained by HCl co-flow; however, the HCl/GeH4 ratio is constrained because excess HCl reduces growth rate and attacks the SiGe layer at sidewall edges. Temperature uniformity across the wafer is held within ±2 °C because germanium incorporation in this regime is strongly temperature dependent. Films are metrology-controlled by high-resolution X-ray diffraction for thickness and Ge content, secondary ion mass spectrometry for carbon and boron depth profiles, and four-point probe for sheet resistance. The resulting base stack is embedded in BiCMOS RF front-end modules operating in the 28 GHz and 39 GHz 5G bands, with reliability screening performed under JEDEC JESD22-A104 temperature cycling and JEDEC JESD22-A110 highly accelerated stress test conditions. Germane source gas conforms to SEMI C3.52 with minimum purity 99.999%, and the delivery line is constructed from electropolished 316L stainless steel with surface roughness below 0.25 μm Ra to minimise particle shedding and surface adsorption.
In recessed pMOS source/drain processing, selective Si1-xGex epitaxy is performed after dry etching of source/drain cavities and before silicide formation. The epi tool is a reduced-pressure cluster reactor with wafer temperature of 600–650 °C for dichlorosilane-based SiGe deposition or 500–600 °C for silane-based deposition; total pressure is maintained below 20 Torr. Germane feed fraction is increased until the film reaches 25–45 at% germanium, because uniaxial compressive stress in the silicon channel rises with germanium substitution. In-situ boron doping is controlled to 1×10²⁰–1×10²¹ cm⁻³ through diborane flow. The main process conflict is between strain retention and film relaxation: at Ge fractions above 30 at%, the equilibrium critical thickness on Si(001) falls below 20 nm, but recess cavities often require fill depths of 40–70 nm. Metastable growth is therefore used at the lowest thermal budget that still permits selective epitaxy. HCl is added at flow ratios sufficient to suppress nucleation on nitride spacer and silicon dioxide hardmask surfaces, but excess HCl lowers growth rate and creates faceting at the pattern edge. In-line bright-field and dark-field wafer inspection is used to detect selectivity loss and nodules, while high-resolution X-ray diffraction monitors Ge composition and strain relaxation. After epitaxy the wafer proceeds to rapid thermal processing for dopant activation, but anneal thermal budget is limited because Ge diffusion and stress relaxation degrade channel mobility. Terminal devices are pMOS transistors in FinFET and gate-all-around logic nodes with embedded SiGe stressors. Test structures are evaluated with ID,sat measurements and cross-sectional transmission electron microscopy for interface quality. Precursor quality is covered by SEMI C3.52 for germane and by point-of-use purifiers that remove moisture and oxygen from the delivery line before the mass flow controller.
When the same precursor set is used to deposit Si/Si1-xGex superlattices for gate-all-around nanosheet release, germane must be switched repeatedly with silane while maintaining abrupt composition transitions. The superlattice is grown at 500–600 °C, with each SiGe sacrificial layer 5–15 nm thick and Ge fraction 20–40 at%. The film stack is deposited in a reduced-pressure epitaxy reactor at total pressure below 20 Torr, using germane in hydrogen and dichlorosilane or silane as the silicon source. Abrupt interfaces are necessary because the later selective etch for sacrificial SiGe release differentiates silicon from SiGe based on Ge fraction; a graded interface of only 1–2 nm can reduce etch selectivity and cause non-uniform channel release. The competing requirement is that a high Ge fraction increases etch selectivity but lowers the critical thickness and promotes undulation at the Si/SiGe interface. Wafers are monitored by cross-sectional transmission electron microscopy and atomic force microscopy; RMS roughness measured on the superlattice surface is maintained below 0.2 nm. After channel release the sacrificial SiGe is removed using a selective wet or dry etch chemistry that attacks SiGe at high selectivity to silicon. The resulting nanosheet channels proceed to gate stack deposition and are integrated into sub-5 nm logic test vehicles. Published data for the exact etch selectivity of the sacrificial SiGe removal step varies by Ge fraction and etch chemistry; process validation therefore relies on cross-section metrology rather than a single numerical selectivity value. Germane qualification follows SEMI C3.52, and the epitaxial chamber is maintained under cleanroom conditions consistent with ISO 14644-1.
Plasma-activated fiber preform deposition can use germane as a halide-free germanium precursor when low chlorine incorporation and reduced deposition temperature are required. Germane, silane, and oxygen are introduced into a rotating silica substrate tube at reduced pressure, and a 2.45 GHz microwave plasma drives oxidation to SiO₂ and GeO₂. The germane-to-silane ratio is adjusted to give a core GeO₂ concentration from 3 mol% to 10 mol%. The refractive index increase relative to pure silica is approximately 0.0014 per mol% GeO₂, producing Δn values of 0.004 to 0.014 across the core. Gas-phase pre-reaction must be suppressed because particulate soot deposited on the tube wall increases optical scattering loss. Deposition rate, plasma power, and pressure are therefore controlled within narrow windows rather than maximised. The preform is later consolidated and drawn into single-mode fiber meeting ITU-T G.652.D or bending-insensitive ITU-T G.657.A2 attenuation and mode-field specifications. Attenuation at 1310 nm and 1550 nm is the primary acceptance criterion; excess GeO₂ clustering and chlorine contamination are inspected by refractive index profiling and optical time-domain reflectometry on the drawn fiber.
| GeO₂ concentration (mol%) | Approximate Δn at 589 nm |
|---|---|
| 3 | 0.004 |
| 6 | 0.008 |
| 10 | 0.014 |
Germanium-on-silicon photodetector fabrication uses a two-step germane epitaxy sequence to manage the 4.2% lattice mismatch between Ge and Si. A low-temperature seed is first deposited at 350–400 °C to 30–60 nm using germane in hydrogen, creating a continuous but defect-rich wetting layer. The wafer is then ramped to 600–700 °C for bulk germanium growth to 1–2 μm, during which threading dislocation density is reduced through growth-front annealing and thermal cycling. Germane flow is maintained with a mass flow controller, and the chamber is a single-wafer or small-batch UHV-CVD/RPCVD system with base pressure below 1×10⁻⁹ Torr before growth. In-situ doping is supplied by phosphine for n-type regions and diborane for p-type contacts. The terminal device is a normal-incidence PIN photodiode for 1310 nm and 1550 nm optical transceivers; because the germanium absorption coefficient is lower at 1550 nm than at 1310 nm, sufficient germanium thickness is required for responsivity. Dark current density depends on threading dislocation density and electric field; process development monitors dark current at −1 V reverse bias and responsivity at 1550 nm under optical power calibrated to NIST-traceable standards. Qualification follows Telcordia GR-468-CORE for optoelectronic components. Cylinder change on the germane delivery system requires inert purging and valve-packing checks because moisture ingress promotes germanium oxide or germanium dioxide particulate formation in downstream mass flow controllers.
Amorphous silicon-germanium thin-film photovoltaic deposition uses a parallel-plate PECVD chamber at 200–300 °C and 0.1–1 Torr, with germane mixed into silane and hydrogen. The germane-to-silane flow ratio is adjusted to shift the optical band gap from approximately 1.7 eV for amorphous silicon toward 1.0 eV for amorphous germanium. Middle and bottom absorber layers in multi-junction cells typically use band gaps of 1.5–1.6 eV and 1.3–1.4 eV, respectively. Hydrogen dilution is maintained at 10–40 times the hydride flow to passivate dangling bonds and reduce defect density, but higher germane fractions reduce deposition rate and can increase light-induced degradation. The process is operated at the highest germanium fraction that still yields measurable photoconductivity gain, and film quality is checked with dark conductivity, Tauc-plot optical band gap, and subgap absorption by constant photocurrent method. Large-area modules are deposited on glass or flexible substrates using multi-chamber cluster tools; uniformity is monitored across substrate widths of 1.5 m or greater. Finished thin-film modules are tested under IEC 60904-3 reference spectral irradiance and qualified according to IEC 61215-1-3 for thin-film design qualification. The main operational boundary for germane in this application is that high gas-phase depletion at high germane fractions creates non-uniform germanium incorporation across large-area electrodes; showerhead spacing and RF power must be re-optimised for each new hydride ratio.
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Germane (GeH4) Electronic/EL Grade is a high-purity gaseous germanium precursor supplied as a liquefied compressed gas for semiconductor and optoelectronic deposition processes. The product is specified at a nominal purity of 99.999% (5N) with moisture and oxygen thresholds below 1 ppmv; certificates of analysis are generated for each cylinder using gas chromatography with pulsed discharge helium ionization detection, Fourier transform infrared spectroscopy, and cavity ring-down spectroscopy. Commercial model designators are supplier-specific and typically encode chemical identity, grade, purity, and cylinder size. A typical ordering nomenclature may contain the string GeH4-EL-5N followed by the water capacity in litres; procurement specifications should require the full certificate of analysis rather than relying solely on the trade designation.
Electronic/EL Grade indicates a purity and packaging class intended for electronic device and optoelectronic fabrication. The designation does not imply a single standardized specification across gas suppliers; it is a commercial grade indicator that must be read with the certificate of analysis. Cylinder packages of 2.2 L, 10 L, and 47 L water capacity are supplied in 316L stainless steel with electropolished internal surfaces. At 25 °C and 1 atm, the gas density is 3.13 g/L, and vapor density relative to air is 2.65. The vapor density greater than air means released germane accumulates in low areas, which drives gas cabinet exhaust location and sensor placement. The boiling point of -88.4 °C and critical temperature of 34.85 °C define the compressed liquefied gas classification; the cylinder must never be overfilled beyond the established filling density. The product is intended for chemical vapor deposition of SiGe and Ge films, optical fiber preform doping, and related processes where volatile metal and dopant impurities must remain below the detection limits of atmospheric pressure ionization mass spectrometry.
The specification limit is not a single universal value; it is defined by the end-use process window and by the analytical capability of the gas supplier. Table 1 summarizes representative industry acceptance limits for Electronic/EL Grade GeH4. Actual certificate values vary by supplier and cylinder batch, and low-moisture variants are available for high-mobility germanium channel applications. Because conventional gas chromatography with thermal conductivity detection cannot resolve low-part-per-million impurities, high-sensitivity methods are required.
| Parameter | Representative value | Analytical method |
|---|---|---|
| Germane purity | ≥ 99.999% (5N) | GC-PDHID |
| Oxygen (O2) | ≤ 1 ppmv; low-moisture variants ≤ 0.5 ppmv | GC-PDHID, APIMS |
| Water (H2O) | ≤ 1 ppmv; low-moisture variants ≤ 0.5 ppmv | CRDS, FTIR |
| Carbon dioxide (CO2) | ≤ 0.5 ppmv | GC-PDHID |
| Carbon monoxide (CO) | ≤ 0.5 ppmv | GC-PDHID |
| Total hydrocarbons (THC) | ≤ 0.5 ppmv | GC-FID |
| Nitrogen (N2) | ≤ 2 ppmv | GC-PDHID |
| Molecular weight | 76.62 g/mol | Calculated |
| Boiling point at 1 atm | -88.4 °C | NIST reference |
| Gas density at 25 °C, 1 atm | 3.13 g/L | Calculated |
| Vapour density relative to air | 2.65 | Calculated |
Representative values are included for preliminary feasibility assessment; the certificate of analysis for a specific cylinder is the controlling document.
Delivery of Electronic/EL Grade GeH4 is performed through gas panels constructed from 316L stainless steel with electropolished wetted surfaces having surface roughness below 0.25 µm Ra. Diaphragm valves with low dead-leg geometries and mass flow controllers calibrated for germane are used. Cylinder change is conducted under high-purity nitrogen purge in an environment meeting ISO 14644-1:2015 Class 5. The gas cabinet is monitored with electrochemical or metal-oxide sensors, and exhaust is routed through a dedicated abatement system. These measures reduce oxygen and moisture ingress and prevent formation of germanium oxide particles that clog mass flow controllers.
Residual oxygen in germane creates GeOx and increases particle count; moisture participates in hydrolysis of germane to germanium hydroxide species. The electronic grade differs from industrial germane by lower oxygenated species and hydrocarbon levels, reducing intermittent particle shedding in 300 mm high-aspect-ratio features. Analytical confirmation is performed by GC-PDHID for permanent gases, FTIR for germane and digermane, and CRDS for moisture. Published data for specific impurity interactions in high-rate epitaxy is limited; therefore, end users should verify impurity budgets against the certificate of analysis for each cylinder.
Analytical method validation is conducted under a quality system compliant with ISO 9001; calibration gas traceability is maintained through gravimetric standards. Detection limits are matrix-dependent because germane is a reactive gas; moisture analyzers are protected from germanium oxide deposition by heated sampling lines and filtered sample cells. Calibration gas blends for germane are prepared gravimetrically and cross-checked by FTIR or APIMS.
Batch-to-batch variance in germane impurity profiles has been observed when cylinder pre-treatment is incomplete; a higher oxygen spike in the initial 5% of cylinder effluent can occur if the internal surface was not passivated. Production lines often precondition by venting the initial charge through the abatement line until the moisture analyzer reading stabilizes below 100 ppb. The use of a dedicated vent line prevents backstreaming from shared abatement headers.
Internal cylinder surfaces are passivated and baked before filling; evacuation to 10-5 Torr or lower is performed prior to product fill. The cylinder remains under a positive nitrogen pad pressure after filling. Because germane can react with surface oxides to form germanium oxide and hydrogen, cylinders are stored below 40 °C and handled with regulators made from 316L stainless steel or Hastelloy C-22. Elastomeric seals are not used on germane wetted surfaces; metal face-seal fittings are required. Gas cabinets used for germane should be dedicated or cross-purged to avoid contamination by oxidizing gases. Incompatibilities include oxygen, chlorine, fluorine, nitrous oxide, and halogenated cleaning plasmas.
Moisture ingress during cylinder change becomes significant at relative humidity above 60%; connections should be bag-purged with dry nitrogen and tightened according to the fitting manufacturer's torque specification. Pressure transducers and valve seats exposed to germane are selected for low internal volume to reduce decomposition residue accumulation.
Selection between germane and digermane is governed by the minimum deposition temperature and the acceptable carbon/chlorine budget. Germane has a higher decomposition onset than digermane but lower than silane; therefore, SiGe films with germanium fractions from 10% to 60% are deposited using GeH4/SiH4 mixtures. In UHV-CVD, substrate temperatures from 450 °C to 650 °C and total pressures from 0.1 Torr to 10 Torr are used. Digermane may be selected for sub-400 °C Ge or GeSn deposition, but its lower vapor pressure increases delivery complexity and condensation risk in gas lines. GeCl4 is a liquid source used primarily in optical fiber preform oxidation, where chlorine is removed by hydrolysis; residual chlorine is incompatible with front-end semiconductor processing.
| Parameter | GeH4 Electronic/EL Grade | Digermane (Ge2H6) | Germanium tetrachloride (GeCl4) |
|---|---|---|---|
| Physical state at 25 °C | Compressed liquefied gas | Volatile liquid, low vapour pressure | Liquid |
| Typical deposition temperature window | 450–650 °C for SiGe; 350–500 °C for Ge on heated substrates | Lower than germane, sub-400 °C reported | Flame hydrolysis / oxidation above 800 °C |
| Residual dopant risk | Low oxygen and hydrocarbon content | Higher cost, lower volatility | Chlorine residue risk in semiconductor films |
| Typical purity | ≥ 5N | 4N to 5N | 4N to 5N |
In a load-locked cold-wall reduced-pressure chemical vapor deposition chamber configured for 300 mm wafers, germane is introduced through a radial gas distribution showerhead with silane and hydrogen carrier gas. The growth rate of SiGe is controlled by total pressure, substrate temperature, and the GeH4/SiH4 flow ratio. At a substrate temperature of 550 °C and total pressure of 1 Torr, germanium incorporation increases nonlinearly with germane partial pressure; growth rate and germanium fraction are tool-dependent and are established by design-of-experiment runs for each reactor. Mass flow controllers are periodically span-verified because thermal sensor drift from germanium deposits is a known production-scale problem. The showerhead temperature is maintained above the condensation point but below the decomposition onset to reduce clogging.
In plasma-enhanced chemical vapor deposition, germane diluted in hydrogen or helium is used at lower substrate temperatures, typically below 300 °C, to deposit amorphous germanium for near-infrared photodetectors. In optical fiber preform fabrication, germane is reacted with oxygen in a modified chemical vapor deposition torch to form GeO2-doped silica glass; the electronic grade is selected when low transition-metal contamination is required for low optical attenuation at 1550 nm.
A process conflict exists between high GeH4 partial pressure for increased growth rate and gas-phase nucleation causing particle defects on wafer edges and showerhead surfaces. In reduced-pressure epitaxy, germane can undergo homogeneous decomposition if the local partial pressure exceeds a chamber-specific threshold. The threshold is influenced by total pressure, substrate temperature, showerhead-to-wafer spacing, and carrier gas composition. In-line particle monitors and optical emission spectroscopy are used to detect the onset of gas-phase nucleation. If the threshold is exceeded, growth rate may continue to increase while device yield decreases; this is a critical control boundary rather than a hard physical limit.
Selective epitaxial growth of SiGe source/drain stressors requires addition of HCl in the deposition chemistry to suppress germanium and silicon nucleation on SiO2 or SiN masks. The GeH4/HCl ratio is process-specific; excessive HCl reduces growth rate and may alter germanium incorporation. In-line particle monitors are used to detect gas-phase nucleation when germane partial pressure exceeds the reactor-specific stability limit. Temperature deviations of more than ±5 °C from the optimized setpoint have been shown to shift growth rate and germanium fraction in production reactors; published data for this specific configuration is limited, so chamber qualification is performed on a regular basis.
Germane is a flammable, toxic gas that can form explosive mixtures with air and may ignite when released from high-pressure sources. Continuous gas detection is required in storage and distribution areas. Cylinders should be secured, used in gas cabinets, and never connected to systems containing oxidizers unless an inert purge and isolation sequence has been completed. Storage areas are segregated from oxidizers and halogenated gases, and cylinders are grounded to prevent static discharge. Vent lines from pressure relief devices are routed to a dedicated abatement system capable of handling germane decomposition products. The product should not be heated above 40 °C, because cylinder pressure rises and decomposition can occur. A minimum cylinder pressure of 50 psig is often maintained to prevent backflow contamination; below this pressure, residual impurities may concentrate in the liquid phase and alter the delivered gas quality. End users must consult the safety data sheet and local fire code for exposure limits, cylinder segregation, and abatement requirements.
