Quantum near field probe for integrated circuits electromagnetic interference at wafer level

Abstract

With the complexity and integration of integrated chips increasing, existing integrated circuits electromagnetic interference techniques using metallic probes cannot meet the emerging demand at single die level or wafer level, which requires micron spatial resolution and ultraweak invasiveness. In this article, we developed a non-invasive near field probe in the fiber format using nitrogen-vacancy center in diamond, which was attached to the tip of fiber as microwave B-field sensing element. Subsequently, we applied the fiber diamond probe to near field scanning of a low noise amplifier chip and a power amplifier chip. Through numerical simulation, we find that the surface field strength is proportional to current density at chip surface, thus this probe can be used as a current imaging technique at microwave frequency.

Application of single photon counter module in weak signal detection for RF chip scanning using a quantum near field probe

“…Once excited, the NV center generates 637 nm red fluorescence, which returns along the same light path, but passes through the dichroic mirror to get focused in the receiving area of SPCM. It is worth mentioning that in the fabrication of fiber probes, we detected the fluorescence intensity by spectroscopy and found that the thinning of the fiber ends could significantly enhance the fluorescence 10 . The fiber probe is therefore specially tapered to improve the efficiency of fluorescence collection, leading to the suppression of photon shot noise 18 .…”

“…It is worth mentioning that in the fabrication of fiber probes, we detected the fluorescence intensity by spectroscopy and found that the thinning of the fiber ends could significantly enhance the fluorescence. 10 The fiber probe is therefore specially tapered to improve the efficiency of fluorescence collection, leading to the suppression of photon shot noise. 18 In addition, the optical module is designed to eliminate the interference of miscellaneous light.…”

“…5 In the previous work, the NV center-based method for microwave field imaging has been applied to several devices such as circular loop, 6 spiral antenna, 7 patch antenna, 8 CPW, 9 and amplifier chip. 10 One of them 6 characterizes the magnetic field sensitivity of the current loop antenna and uses a Thorlab NEL01 absorber to stabilize the laser and reduce the laser noise, which is a completely different method of noise reduction from our work. The other 7 is microwave near-field imaging of the NV center with a CCD camera, which has higher time efficiency and stability because it does not have any moving parts, but the measurement method is at a certain distance from the measured object and does not have the high resolution of the tapered fiber probe used in this paper.…”

“…Recently, quantum near‐field probes using NV center in diamonds 4 have been demonstrated, which has an unprecedented spatial resolution of micron and brings little disturbance to the chip under test 5 . In the previous work, the NV center‐based method for microwave field imaging has been applied to several devices such as circular loop, 6 spiral antenna, 7 patch antenna, 8 CPW, 9 and amplifier chip 10 . One of them 6 characterizes the magnetic field sensitivity of the current loop antenna and uses a Thorlab NEL01 absorber to stabilize the laser and reduce the laser noise, which is a completely different method of noise reduction from our work.…”

Surface H‐field mapping of a microwave limiter chip based on quantum diamond probe

“…6 We developed a magnetic current imaging (MCI) technique at microwave frequency in this work. The current density is linearly proportional to the surface Hfield of the chip 7,8 which is sensed by a fiber quantum probe, a diamond crystal containing nitrogen-vacancy (NV) center attached to the tip of a tapered fiber. This probe is an essential extension of the commercial nearfield H-probe, which is metallic, bringing some distortion to the electromagnetic field of the chip under test.…”