The probe station unit has undergone numerous technological advances over the past decade. Researchers now have more options to choose from which is beneficial but can make it difficult to effectively compare unique probe station units prior to purchasing. This tool represents a significant financial investment so it is important to select the best solution for today and tomorrow. Fortunately, focusing on five key characteristics can make the comparison process easier and more accurate.
1. With the growing popularity of cryogenic measurements time-consuming wiring of an on-wafer device is no longer necessary. Today's platforms allow for visualization and electrical interrogation of multiple wafer level devices. Unfortunately, this comes with a trade-off. Optical access to inflexible probing of a device can transfer heat loads from the probe arm to the device being tested. To minimize this effect, it is essential the probe station unit has some type of shield or other technology to reduce thermal radiation on the sample. Multiple experiments have shown that even the smallest amount of thermal radiation transfer can alter the end results.
2. Another characteristic to compare before purchasing a probe station unit is the ability to make adjusted variable temperature measurements. Traditionally, probe arms are anchored to the sample stage and the probe tip will move as the sample stage warms. This makes it difficult to automate variable temperature measurements because the probes must be lifted and re-landed for any noticeable temperature transition. The ability to create stable tip position which allows for continuous measurements is critical. Not only does it ensure accuracy but it also provides increased measurement functionality.
3. The sample holders on the probe station unit must be compared as well. Most units offer a variety of sample holders to choose from. Popular options include a grounded sample holder, co-axle sample holder, and isolated sample holder although several additional options are available as well. When comparing units, it is critical to ensure researchers can use the necessary sample holder required to accurately complete their experiment.
4. The probe station units' vision system is critical to compare before purchasing. This system is responsible for distinguishing characteristics of the sample and properly landing probes. Depending upon the experiment the level of detail provided by the vision system varies. Thus, researchers must consider current experiments as well as future needs when comparing vision systems.
5. The final character to compare before purchasing a probe station unit is overall system versatility. Considering the significant upfront cost, it is imperative researchers make the most out of their unit by selecting an option which allows for successful research utilizing a variety of methods. As more probe station units become customizable or modular overall flexibility and research capabilities continue to expand.
Considering the significant financial investment required to purchase a quality probe station unit it is not surprising how much time and resources are used to accurately compare available options. By focusing on the five key characteristics an accurate comparison can be completed quickly and easily.