NON MECHANICAL PROBED TEST ELEMENT GROUP (TEG)
Original Publication Date: 2000-Feb-01
Included in the Prior Art Database: 2003-Jun-18
It needs about two or three months to make semiconductor devices in whole wafer level. There are TEGs (Test Element Group) between product chips on the silicon wafer. We test them for monitoring semiconductor device characteristic during processing in the clean room. To measure TEGs during process is the most effective method to monitor the semiconductor manufacturing line is stable. Now, we need mechanical probing to measure them (see Fig.1). In this case, we probe aluminum pads with tungsten needles. And we must little bit scrub to get good contact between tungsten needles and aluminum pads. However, to scrub makes many aluminum particles. They fall on the wafer surface and make defects in the electrical circuit of the semiconductor devises (see Fig.2). The defect makes reliability problems. We propose a new method and a new design of TEGs useing Laser bean and Electron bean in the vacuum chamber to so We can test the TEGs without mechanical probing by using our method. Fig.3 shows schematic diagrams of our proposal. For example, we apply voltage (or current) and measure the curre chain resistance. In our proposal, first we prepare large PN-junction for voltage (or current) supply (for examp We call it the optical cell. Next, we inject Laser beam which energy is over the silicon band gap energy (1.12eV The generated voltage is estimated about 0.6 0.7 Volts. Maximum current depends on the optical cell size. We n voltage and enough current.