Lakeshore CRX-EM-HF - User Manual

Lake Shore Cryotronics, Inc. 575 McCorkle Blvd Westerville, Ohio 43082
Tel: (614) 891-2244 Fax: (614) 818-1600 e-mail: info@lakeshore.com www.lakeshore.com
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CRX-EM-HF Probe Station Instructions
Introduction
The Lake Shore Model CRX-EM-HF probe station combines the magnetic field capability of the Model EMPX-HF
probe station with the cryogen free capability of the model CRX-4K. The CRX-EM-HF is for non-destructive testing
of devices on full and partial wafers up to 25mm (1 in) in diameter. Based on a two-stage Gifford McMahon closed
cycle refrigerator (CCR), the CRX-EM-HF provides up to a ±0.6 T magnetic field over a temperature range of <8 K to
400 K standard or <20 K to 500 K with optional PS-HTA-EM high temperature stage.
Figure 1: CRX-EM-HF probe station
Rev 1.1 P/N 119-510 March 24, 2014

Summary

Introduction

Specifications

System Overview

Installation and Setup

Site Requirements

Requirements for installing the instrument console, CCR, and electromagnet.

Unpacking the Probe Station

Guide for uncrating and unpacking the probe station.

Utility Connections

Utility connections for the instrument console, CCR, and electromagnet.

Assembling a Basic Probe System Configuration

Steps for assembling the probe station configuration.

Installing and Removing Probes

Instructions for installing and removing probes.

Re-configuring the Sample Stage

Configuration options for the sample stage rotation.

System Verification and Testing

Basic Operation

Temperature Limits

Maximum temperature limits for probe station components and stages.

Vacuum, Probing, and Sample Operation

Procedures for vacuum, probe arm, sample exchange, and probing.

Temperature Operation

Details on operating the probe station at various temperatures.

Controls for Temperature Operation

Information on CCR and electronic controls for temperature operation.

Cooling the Probe Station to Base Temperature

Procedure for cooling the probe station to its base temperature.

Operating the Sample Stage from Base Temperature to 350 K

Steps to operate the sample stage from base temp to 350 K.

Operating the Sample Stage from 350 K to 400 K

Steps to operate the sample stage from 350 K to 400 K.

Magnetic Field Operation

Optional 360° Rotation Stage Operation

Operation of the optional 360° rotation stage for sample alignment.

Advanced Operation

Optional High Temperature Stage

Details on the optional high temperature stage for extended temperature range.

Configuring for HT Stage Operation

Steps to connect and configure the HT sample stage.

Connections to the Probe Station

Detailed steps for making electrical connections for the HT stage.

Reconfigure Temperature Controller for HT Stage

Reconfigure Model 336 for HT Stage

Verifying and reconfiguring the Model 336 temperature controller for HT stage use.

Re-configuring the Sample Stage

Re-configuring the sample stage for the HT stage.

HT Stage Installation

Procedure for installing the HT stage adapter and the HT stage.

HT Stage Removal and Controller Reconfiguration

Install the HT Sample Stage

Aligning and installing the HT sample stage onto the adapter.

HT Stage Removal

Procedures for removing the HT stage and its adapter.

Reconfigure Controller for Standard Operation

Reconnecting the temperature controller for standard operation.

Temperature Operation with HT Sample Stage

Cooling with HT Sample Stage

Procedure for cooling the probe station with the HT sample stage installed.

Operating HT Stage at Base Temperature

Operating the HT sample stage at base temperature conditions.

Operating HT Stage from 20 K to 300 K

Procedures for operating the HT sample stage from 20 K to 300 K.

HT Sample Stage Operation (300 K to 500 K)

Station Warm Up

Maintenance and Troubleshooting

Maintenance and Troubleshooting References

References for maintenance and troubleshooting procedures for CCR and probe station.

Contacting Lake Shore

Information on how to contact Lake Shore Systems Service for assistance.

Overview

1. Function Description
2. Important Technical Specifications
3. Usage Features
4. Maintenance Features

The Lake Shore Model CRX-EM-HF probe station is a sophisticated instrument designed for non-destructive testing of devices on full and partial wafers up to 25mm (1 inch) in diameter. It combines the magnetic field capabilities of the EMPX-HF probe station with the cryogen-free operation of the CRX-4K model, offering a versatile platform for various research and development applications.

Function Description

The CRX-EM-HF probe station provides a controlled environment for electrical and magnetic characterization of samples at cryogenic temperatures and in the presence of magnetic fields. At its core, it utilizes a two-stage Gifford McMahon closed cycle refrigerator (CCR) to achieve low temperatures. The system allows for precise probing of samples using up to four probe arms, enabling a wide range of electrical measurements. The integrated electromagnet provides a horizontal magnetic field, crucial for studying magnetotransport and other magnetic phenomena. The system is designed for ease of use, with features like a vision system for precise probe placement and options for sample rotation.

Important Technical Specifications

• Sample Cooling Assembly:
  • Type: 2-stage (sample + radiation shield)
  • Radiation Shielding: Radiation shield with top viewport surrounds the sample.
  • Cooling Source: 2-stage closed cycle refrigerator (CCR) with 1 W cooling power at 4.2 K.
• Temperature:
  • Standard Range: 8 K to 400 K
  • Optional Range (PS-HTA-EM): 20 K to 500 K
• Vacuum: 10⁻⁵ Torr at base temperature.
• Cycle Time: 4.5 hours
• Vacuum Pump Down: 0.5 hours
• Station Cooldown: 2.25 hours
• Station Warmup: 1.75 hours
• Vibration at Sample: <1 µm
• Sample:
  • Maximum Sample Size: 25.4 mm (1 inch) diameter
  • Sample Backside Optical Access: Not an option
  • Sample Rotation (Optional PS-360-CRX-EM): 360-degree rotation stage. This option adds a 2 K gradient from the sample stage to the top of the rotation stage at base temperature.
• Probing:
  • Maximum Number of Probes: 4 (see orientation diagram on page 3)
  • Cooled Probe Mounts: <20 K with sample at base temperature
  • DC/RF Probes: Electrical isolation >100 GΩ for low leakage measurements
  • Microwave Probes: Frequency range DC up to 67 GHz
  • Fiber Optic Probes: Available for electro-optical measurements
• Magnetic Field:
  • Field Capability: ±0.6 T
  • Field Orientation: Horizontal (parallel to the sample plane)
• Load Lock: Not an option
• High Vacuum: Not an option

Usage Features

The CRX-EM-HF probe station offers several features that enhance its usability and versatility:

• Temperature Control: The system allows for precise temperature control of the sample stage, radiation shield stage, cryocooler stages, and probe arms. It supports both standard (8 K to 400 K) and optional high-temperature (20 K to 500 K) operation. The Model 336 temperature controller is used for managing these temperatures, with specific settings provided for different temperature ranges and operational modes (e.g., cooldown, maintaining base temperature, warming up).
• Magnetic Field Operation: The electromagnet coils provide a horizontal magnetic field up to ±0.6 T. Operating instructions for the magnet are referenced from the EMPX-HF manual.
• Sample Rotation (Optional): The optional 360° rotation stage allows for continuous rotation of the sample relative to the magnetic field. This is manually actuated by a control knob with a 30:1 gear ratio, enabling precise angular alignment. Notches at 90° increments on the rotation stage aid in gauging rotation.
• Probe Arm Control: The system includes four probe arms with individual controls for precise positioning. The probes are aligned at 30° angles due to the magnet pole location, which may limit probe tip proximity depending on the probe type.
• Vision System: An optics package and vision system are integrated for accurate placement and manipulation of probes on the sample.
• High Temperature Stage (PS-HTA-EM): This optional stage extends the operating temperature range to 500 K. It features a coaxially isolated design with a platinum sensor and two 50 W heaters. Specific procedures are outlined for its installation, electrical connection, and temperature control, including the need to remove probe holder thermal anchors for operation above 350 K to prevent overheating of the probes.
• Safety Precautions: The manual emphasizes several safety warnings, including not operating the sample stage above 350 K indefinitely with thermal anchors connected, observing a 5 K/min ramping rate for temperature changes to prevent damage to the HT stage, and monitoring probe arm sensors when operating the HT stage above 350 K. The Model 336 temperature controller has built-in temperature limits to prevent system shutdown.

Maintenance Features

The manual provides comprehensive guidance on maintenance and troubleshooting, referencing sections from the CRX-4K and EMPX-HF manuals:

• Routine Maintenance: Information for routine maintenance is provided, covering both general system components and specific CCR maintenance.
• Troubleshooting: Detailed troubleshooting information is available for vacuum operation, general system issues, and probe station cooling problems.
• Technical Support: Lake Shore Cryotronics offers technical support through their Systems Service department, available Monday through Friday during business hours. Users can contact them via phone, fax, email, or by completing an online service request form for efficient problem resolution.

The CRX-EM-HF probe station is a robust and flexible tool, designed to meet the demanding requirements of cryogenic and magnetic field measurements, with clear instructions for setup, operation, and maintenance to ensure optimal performance and longevity.

Lakeshore CRX-EM-HF Specifications

General

Brand	Lakeshore
Model	CRX-EM-HF
Category	Industrial Equipment
Language	English