The growing miniaturization and output density of semiconductor components is resulting in increasingly high requirements for the cleanliness of starting materials. As well as reducing the efficiency of the components, the tiniest traces of foreign elements can significantly shorten their service life. The VPD systems from PVA Metrology & Plasma Solutions allow our customers to detect these trace elements before and during the process chain on the wafer with detection limits of up to 1E7 at/cm². As a result, disruptions to production can be identified at an early stage and unnecessary additional costs can be avoided. This means that MPS systems pay for themselves quickly.
- VPD (Vapor Phase Decomposition)
- Modular Design
- WSPS (Wafer Surface Preparation System)
- WSMS (Wafer Surface Measurement System)
VPD (Vapor Phase Decomposition) Technology
With VPD technology, the surface of the substrate material is broken down in the gaseous phase and the reaction products are discharged. Usually, the contamination previously present in the removed material is not transferred to the gaseous phase and remains on the surface. In the subsequent step, a fluid is dripped over the surface, where it gathers up the remaining impurities. The content of the drops can be analyzed by an ICP-MS or a TXRF, for example.
- Modular design
- The modules can be used individually or in fully automatic combination in different-sized system housings
- Design as an analysis system with integrated ICP-MS
The modular concept is based on modules for various applications and all common wafer sizes. Modules are available for etching the backing layer on the wafer (PAD Fume), for scanning the wafer with the VPD drops to gather the contamination (PAD Scan) and for driving out the fluid of the scan solution for the TXRF analysis (PAD Dry). The latter can also be used to drive out disruptive compounds before scanning or traces of moisture before evacuating the wafer.
There are numerous options for configuring these modules. Here are some examples:
- PAD Fume S allows etching of bulk material with HF/ozone
- PAD Dry T is used for driving out ammonium fluoride after etching of nitride layers
- PAD Scan B additionally enables etching and scanning of the wafer edge including a small area of the front and back of the wafer
- PAD Scan Y enables scanning of hydrophilic surfaces
- PAD Scan E is used to reduce the unwanted Si matrix in the VPD drops
WSPS (Wafer Surface Preparation System)
The WSPS system maps the entire VPD process chain in which the processes or modules in a compact system housing fitted with FFU units are supplemented by the corresponding infrastructure.
Advantages at a glance:
- Highly automated execution of the entire process chain under cleanroom conditions through loading stations, pick-and-place robots, intermediate storage devices & media provision
- Central control of the entire system from the jobs to be performed and definition of the recipes to gathering of all data
- External access for control and monitoring purposes is possible
WSMS (Wafer Surface Measurement System)
The WSMS system constitutes an enhancement of the WSPS series and combines VPD technology with the outstanding detection limits of the WSPS series with a fully integrated ICP-MS.
Advantages at a glance:
- All media, from the chemicals for VPD to calibration of the ICP-MS, are provided fully automatically by the system
- This minimizes risks to staff and the product through contamination and operating errors
- Reduced staff costs: The central host computer controls the entire system, allows control of all components remotely or via SECS/GEM, and provides results in real time.