Agilent On-Wafer Parametric Measurement 4-On-Wafer Parametric Measurement c20130117 [1] free download

File name On-Wafer Parametric Measurement 4-On-Wafer_Parametric_Measurement c20130117 [1].pdf

Excerpt Edition This PDF is an excerpt from Chapter 4 of the Parametric Measurement Handbook. The Parametric Measurement Handbook Third Edition March 2012 Chapter 4: On-Wafer Parametric Measurement "One must learn by doing the thing; for though you think you know it, you have no certainty until you try." -- Sophocles Introduction The vast majority of parametric measurements are performed on-wafer. Obviously, this implies that you need some sort of a wafer prober to make these measurements. What is often missed by many engineers performing on-wafer parametric measurements are the profound effects that various factors such as the wafer chuck, cables, wafer probes and switching matrix (if used) can have upon their measurement results. Fully automatic versus analytical wafer probers Fully automatic wafer probers are designed to be used in production environ- ments in conjunction with either parametric or functional test equipment. Fully automatic wafer probers can test an entire cassette or FOUP (front-opening unified pod) of wafers at a time, and they have the ability to automatically load and align a wafer for testing. Fully automatic wafer probers are virtually always used with some sort of a probe card and switching matrix. Due to their size, cost, and complexity, fully automatic wafer probers are used almost exclusively in production test environments with high-volume production testers. Since this handbook is primarily focused on parametric test instruments, we will not spend any additional space discussing them. Analytical wafer probers are designed to be used in laboratory environments, and they come in both manual and semi-automatic versions. Manual wafer probers do not possess any electrical motors to automate any part of the wafer alignment and stepping process, but must instead (as their name implies) be manually adjusted each time that you want to move to a new location on the wafer. In contrast, most semi-automatic wafer probers possess the capability to automatically align an individual wafer; however, they typically do not support any sort of autom