[SRA] Spreading Resistance Analysis

Features

SRA, also known as spreading resistance profiling (SRP), is a method in which the sample is obliquely polished at a small angle and two tungsten carbide probes are then brought into contact with the polished surface to measure the resistivity versus depth by lateral scanning. The features are:

Application Examples

Principle of operation

The two probes are brought into contact with the sample surface that has been obliquely polished, and the electrical resistance immediately below them is measured.By comparing with the measured value of the calibration standard sample, the measured spreading resistance is converted into specific resistance 𝜌（Ω・cm）.The carrier concentration（cm³）is calculated using the Thurber curve, which shows the relationship between the specific resistance and the carrier concentration N:

Data examples

The bar above the graph in Figure 2 shows the sample’s layer structure with p and n carriers indicated by pink and green, respectively. File and sample name are shown at the top. Probe load (unit: g), sinθ (θ is the abrasion bevel angle), crystal face direction, and the probe scanning step (μm) are shown below the graph.

Data format of deliverables

Specifications

Items for enquiries

• Purpose and scope of the analysis
• Sample information

1. Number of samples, availability of preliminary samples.
2. Analysis depth, carrier type, sample dimensions, thin film structure including film thicknesses, crystalline plane orientation, presence/absence of laminated film and/or patterned films.
3. Dimensions and position of region of interest (ROI).
4. Additional notes.
5. Expected arrival date of sample(s) and shipping method.

• Delivery date:

1. Desired delivery dates of preliminary and final results.
2. Additional notes.

• Other relevant information

Caution

［SRA］広がり抵抗測定法の分析事例はこちらからご覧ください。