The measurement capabilities of the Automated Non-Contact Thickness Measurement System (APS Series) cover two main dimensions: Core Measurable Parameters and Applicable Test Objects. It features non-contact 3D surface measurement technology, as detailed below:

I. Core Measurable Parameters

The system can accurately detect multiple key geometric parameters related to thickness and deformation, including:

1. Fundamental Parameter: Thickness

2. Thickness Variation Parameters: TTV (Total Thickness Variation)

3. Deformation Parameters: Bow, Warp

4. Other Parameters: The dual-probe chromatic confocal opposing design also enables simultaneous acquisition of information such as TIR (Total Indicated Runout) and LTV (Local Thickness Variation).

Its measurement accuracy is extremely high. Taking the chromatic confocal method as an example:

1. Thickness repeatability in transmission mode reaches 0.02 μm.
2. TTV repeatability in transmission mode reaches 0.015 μm.
3. Bow and Warp repeatability can be as low as 0.3 μm.
4. Under the spectral interferometry method:
5. Thickness measurement range is 0.
6. TTV measurement range is only 0.01 μm.

II. Applications of Automated Non-Contact Thickness Measurement Systems

The Automated Non-Contact Thickness Measurement System (APS Series) is primarily applied in various process steps and scenarios within the semiconductor, and it achieves non-contact surface measurement, consumer electronics, and other fields, as detailed below:

1. Annealing Process: Uneven thermal stress distribution due to temperature differences between the upper and lower surfaces or across the glass plate during annealing can easily cause permanent warpage defects. Measuring TTV and Warp helps optimize the annealing temperature curve and reduce residual stress.

2. Chemical Mechanical Polishing (CMP) Process: TTV directly affects polishing uniformity. Excessive thickness variation can lead to localized residual stress or surface roughness exceeding standards. Simultaneously, measuring Bow/Warp prevents uneven distribution of polishing slurry caused by wafer bending.

3. Thin Film Deposition Process: Uneven wafer surfaces can lead to non-uniform thin film thickness, affecting the accuracy of subsequent lithography patterns. TTV measurement ensures thickness consistency of the substrate before deposition, while the Warp parameter controls the impact of overall deformation on thin film quality.

4. Lithography Process: Warpage alters the focus depth of the photoresist, leading to uneven exposure and overlay errors. Real-time monitoring of Bow/Warp allows for optimization of lithography stepper alignment parameters, reducing overlay residuals. Additionally, TTV anomalies may cause insufficient development or sidewall profile defects.

5. Chemical Vapor Deposition (CVD): Plasma-Enhanced Chemical Vapor Deposition (PECVD) Processes: When synthesizing fused silica glass in these processes, TTV measurement is necessary to control deposition uniformity, avoiding cracks or deformation in subsequent processing (e.g., cutting, grinding, polishing) caused by thickness variations.

6. Wafer Loading and Transfer Process: Warped wafers are prone to damaging equipment during automated loading. TTV/Bow/Warp measurement can screen out wafers with excessive deformation, protecting production line yield. For example, silicon carbide wafers require measurement after dicing to optimize grinding and polishing parameters.

7. Surface Flattening Processing: Double-side grinding can correct warpage (correction value ~3.5 μm), while TTV error is greatest at the dicing stage (7.5 μm) and needs to be progressively reduced below 1.5 μm through subsequent copper disc grinding and chemical mechanical polishing.

8. Thinning Process: The release of residual stress during the thinning process can easily cause wafer warpage. Monitoring TTV/Bow is essential to control the thinning amount and avoid the risk of breakage. Measurements before and after the annealing process can quantify the stress release effect.

9. Pre-Packaging Inspection: TTV/Warp parameters affect die bonding accuracy and electrical performance. Packaging factories need to verify that topography parameters meet standards before wafers leave the fab.