SIMS: from research to production control

Abstract

In 1958, when I joined the Philips Research Laboratories, there were a number of technological problems related to the analysis of solids within Philips that needed analytical support. Because the available (bulk) techniques did not give sufficient results, a new technique, later called secondary ion mass spectrometry (SIMS), was launched that involved the bombardment of a solid target with (primary) energetic ions, followed by mass analysis and ion detection of the sputtered (secondary) target ions.The restrictions of the available infrastructure for such an analytical technique were many: there was no PC for data handling, no internet or database for literature search, the photocopying machine was not yet invented, communication with other scientists had to be done by mail (there was no fax, no E-mail, no mobile phones) and, what was worse, SIMS was not considered to be a useful analytical technique compared with established techniques! In the years that followed there were many advances:(1) The SIMS instrumentation was improved by better ion optics, advanced electronic equipment and was extended from sector type to quadrupole and finally to time-of-flight (TOF) mass spectrometers. (2) The methodology of SIMS was developed step by step (parameters such as lateral and depth resolution, detection limit and quantitative analysis were all optimized in turn). (3) The SIMS technique then made its entrance to solve problems in technology development.In the last two decades SIMS has become an indispensable, reliable, quantitative analytical technique for production control in integrated circuit technology and the after-sales care of integrated circuits. The philosophy of the provision of an analytical service at the Philips Research Laboratory (hereinafter referred to as 'our laboratory') is discussed. After the initial period, where every method (SIMS, AES, ESCA, RBS, etc.) was claimed to be 'the only one' (the panacea), we learned how to organize analytical service cost efficiently and for the optimum benefit of the 'customer'. The core analytical techniques were concentrated in one department and the customer would profit from synergy by using several appropriate analytical techniques for the same problem.Today, the latest developments in SIMS instrumentation keep pace with the latest challenges of the ultra-large-scale integration (ULSI) roadmap for integrated circuits, which indicates the dimensions of the circuits that are predicted for the years to come.

A method for quantifying annihilation rates of bulk point defects at surfaces

“…19 We found, however, that the present profiles also suffered from apparent systematic biases within 1 nm of the surface. This approach works well when the error comprises primarily random noise, as is typically the case for SIMS.…”

Experimental measurements of the surface excitation parameters of Cu, Au, Ni, Ag, Ge and Pd based on Si and other reference standard materials

“…Better quality factors were found with Chen's model. 7,8,13 ž The high a chPd values for Pd might be due to slight contamination of the surface, with f c decreasing strongly. ž The IMFPs for Si obtained from EPES measurements with the ESA 31 using Ag, Ni, Cu and Au reference samples, and the f s corrections, are displayed in Fig.…”

SIMS imaging of the nanoworld: applications in science and technology

“…Microfossils of different ages have been compared by SIMS mapping of metabolically important elements as 12 C, 14 N (measured as the 26 CN À fragment ion) and 32 S. 96 These mappings show globules, aligned to form remnant nano-scaled walls of fossiliferous structures (Fig. 5).…”

“…The history of SIMS from its early beginning in the sixties has been recently reviewed by one of the pioneers, Werner. 12 The author clearly states that SIMS development has been originally driven by needs from the electronics and semiconductor industries. Early commercial imaging instruments delivering elemental information at some ten mm scaled lateral resolution were on the market at the end of the sixties: H. Liebl's scanned Ion Probe Mass Analyzer, IMMA, using a double focussing sector field mass spectrometer commercialized by ARL; G. Slodzian's ion microscope for imaging incorporating an ion mirror for energy discrimination commercialized by CAMECA; and a bit later, early in the seventies, ATOMIKA's scanning quadrupole SIMS instrument based on a design developed by K. Wittmaack and J. Maul entered the market.…”