Silicon Wafer Surface Analysis - Organic
Organic contaminants on wafer surfaces must be monitored and controlled because of their detrimental effects on semiconductor devices. The presence of organic contamination can lower breakdown voltage, lead to the formation of silicon carbide, affect oxide growth and quality, cause unintentional doping, contribute to degradation haze formation, and generate post-CVD defects. A recent trend in the industry is to use thermal desorption gas chromatography (TD-GC) coupled with a mass spectrometry detector (MSD) to analyze and identify the volatile and semi-volatile contaminants.
Agilent Technologies: providing complete solutions through strategic partnerships
Through our partnerships with CDS and Gerstel, Agilent can offer you the latest developments in the field of thermal desorption for trapping volatile and semi-volatiles off the wafer surface and other semiconductor components for analysis by GC-MS.
Gerstel Thermo Desorption System (TDS)
The TDS 2 thermo desorption system from Gerstel, Germany, is a multifunctional system for analyzing volatile and semi-volatile substances trapped on an adsorbent and for direct thermal extraction of volatile substances from solids without sample preparation. The CIS functions as a cryotrap, focusing and concentrating the components to be determined, and then transferring them to a capillary column for analysis by GC-MS. Using a combination of cryogenics and high flow-rate desorption, compounds from light gases to C40+ boiling points can be analyzed. With the addition of the TDS A autosampler, the TDS 2 becomes a fully automatic thermal desorption system that can analyze up to 20 samples in one sequence. In addition, automated solventless extraction systems using Solid Phase Micro Extraction and Stir Bar Sorptive Extraction are available. Contact Gerstel at www.gerstelus.com.
For more information, visit the Gerstel Web site.
CDS 300mm Wafer Desorber
The CDS 300mm Wafer Desorber is a specially designed desorption unit for condensable and contamination sampling of semiconductor wafers up to and including 12-inch technology. Using controlled temperature, organic contaminants are volatilized from the surface of a wafer and transported to an Agilent Technologies GC/MS system.
The Wafer Desorber can be coupled with the newest CDS 8000 concentrator, or the multi-channel 6500 bulk sampler. With either instrument, the sample flow is passed through a sorbent trap for concentration prior to automatic transfer of the collected organic compounds to the analytical device.
Rapid heating and cool down of the largest wafer is provided efficiently and uniformly. The chamber design minimizes dead-space allowing for shortened collection times. An optional SilcoSteel interior coating increases sensitivity.
The Wafer Desorber is made to sit vertically on a lab bench to save space. A simple tilt-out system allows loading and unloading of the wafer without breaking and extensive handling. Collection of the sample out of the chamber can be by either vacuum or positive carrier gas flow operation.
For more information, visit the CDS Web site.
Literature
The following Gerstel application notes are available in the Applications section of the Gerstel Web site.
- Quantitative Determination of Trace Analytes in Solid Materials by Thermal Extraction GC
- Comparison of the Sensitivity of Static Headspace GC, Solid Phase Microextraction, and Direct Thermal Extraction for Analysis of Volatiles in Solid Matrices
- An Automated Sorptive Extraction-Thermal Desorption GC-MS System for the Analysis of Aqueous Samples