♦ Customer Requirements: Breaking Through the Temperature Range and Channel Limitations of Conventional Probe Stations

Conventional probe stations are mostly limited to electrical testing at room temperature. However, this customer’s test scenarios involve characterizing electrical transport properties of materials over a broad temperature range from low to high temperatures, facing the following core challenges:

• Lack of in‑situ hot/cold environment: Conventional probe stations do not have active temperature control, making it impossible to perform in‑situ electrical testing during temperature ramping. Transferring samples to separate temperature‑controlled equipment introduces environmental changes and contact deviations.

• Insufficient number of probe channels: Common cold‑hot probe stations on the market are mostly 4‑probe configurations, which cannot easily meet the multi‑channel parallel testing requirements of multi‑electrode devices (such as MOSFETs, Hall bars, and sensor arrays).

• Difficulty in acquiring weak signals: Thermal noise increases at high temperatures, while signal amplitudes decrease at low temperatures. This places extremely high demands on the leakage current level and shielding performance of the probe system. Conventional probe stations find it hard to balance a wide temperature range with low‑noise performance.

• Vacuum and atmosphere compatibility: Samples are prone to oxidation at high temperatures, so tests must be carried out in a high‑vacuum or protective atmosphere. This requires strict sealing and vacuum performance of the chamber.

♦Solution: GoGo Instruments Externally-Adjustable Six-Probe Cold-Hot Stage

GoGo Instruments custom‑developed the six‑probe cold‑hot stage ECH400V‑EB for this user, simultaneously realizing a wide‑temperature cold‑hot environment, six independent probe channels, and ultra‑low leakage current on a single platform. Key specifications are as follows:

1.Cooling/Heating method: Liquid‑nitrogen cooling, resistive heating

2.Temperature range: –190 °C to 400 °C

3.Temperature stability: ±0.1 °C (±0.3 °C from –190 °C to 120 °C)

4.Max heating rate: 150 °C/min

5.Max cooling rate: 40 °C/min

6.Sample stage: Silver, 23×23mm

7.Optical path: Reflection

8.Top window: φ25mm×1mm, CaF₂ (130nm–10 μm), replaceable

9.Probe configuration: Tungsten‑steel gold‑plated coaxial probes×6, leakage current <100fA (at room temperature)

10.Probe adjustment travel: >±5mm

11.Probe interfaces: Triaxial BNC ×6

12.Chamber vacuum level: 5×10⁻⁵ torr

Three Core Advantages:

Advantage 1: Six independently precision‑adjustable probes, breaking the 4‑probe channel limitation

Unlike common 4‑probe cold‑hot stages on the market, the ECH400V‑EB is equipped with six tungsten‑steel gold‑plated coaxial probes, each independently adjustable in XYZ axes via a micrometer head, with a travel range >±5mm. The six‑channel configuration allows simultaneous contact with more electrodes in a single loading, significantly improving testing efficiency for multi‑port devices. This is particularly suitable for scenarios such as Hall devices, multi‑gate MOSFETs, and sensor arrays that require parallel access from multiple probes.

Advantage 2: Wide temperature range in‑situ cold‑hot environment from –190 °C to 400 °C

The system integrates both liquid‑nitrogen cooling and resistive heating modes, covering a broad temperature range from –190 °C to 400 °C, with a maximum heating rate of 150 °C/min and a maximum cooling rate of 40 °C/min. Combined with a silver sample stage (23×23mm) that ensures uniform thermal conduction and a temperature stability of ±0.1 °C, it enables real‑time tracking of the evolution of electrical properties during temperature ramping, filling the gap left by conventional probe stations that lack controllable temperature zones.

Advantage 3: Ultra‑low leakage current design ensuring reliable weak‑signal measurement across a wide temperature range

The use of tungsten‑steel gold‑plated coaxial probes with triaxial BNC interfaces achieves a leakage current below 100fA at room temperature, effectively suppressing electromagnetic interference and leakage currents. Together with a high‑vacuum chamber (5×10⁻⁵ torr) and a CaF₂ window (transmission range 130nm–10 μm), it provides a stable low‑noise environment for high‑impedance measurements of low‑dimensional materials, single‑nanodevices, and similar samples during wide‑temperature‑range ramping.

The six‑probe cold‑hot stage ECH400V‑EB delivered in this project will be integrated into the customer's testing equipment infrastructure, supporting their R&D and production testing needs in semiconductor devices and advanced materials electrical characterization. The GoGo Instruments technical team has simultaneously provided comprehensive operation training and technical documentation support to ensure rapid deployment of the equipment.