A modification of a basic center-tapped magnetic probe design has been developed wherein subtraction of capacitive signals is carried out by the probe itself. The electrostatic rejection of this probe is compared with other typical designs.

No abstract

During 28nm technology node process development, a couple of dozens new thin films and advanced thin film processes have been introduced to meet needs of the CMOS circuit performance. These new films and processes are used for micro-patterning, gap-fill, high-k metal gate (HKMG) work function metals and electrodes, electrical and reliability performance, etc. This article shall report the latest progress in thin film developments at the leading Chinese semiconductor company, SMIC. Some key challenges in the areas mentioned above will be elaborated and various new thin film requirements will be discussed. Examples of some thin film process developments, especially in the micro-patterning, Metal Gate and STI and ILD gap-fill, and HKMG work function tuning, will be provided, and the preliminary results will be presented. Step Coverage and/or Gap-Fill ChallengesSatisfactory step coverage and successful gap-fills have been achieved at STI, metal gate (MG) 1 , contact ILD, and M1/Mx Cu interconnects, the four critical areas of IC fabrication. In the TaN/Ta Cu barrier process, increased side-wall step coverage is usually required for better reliability, and relatively reduced bottom coverage is required for lower Cu via resistance. In contrast, the step coverage requirements for a CMOS work function (WF) metal, TiAl in NMOS as an example, is reversed and a much reduced sidewall coverage is preferred to benefit the MG gap-fill complex. A flattened bottom PVDTiAl film, rather than a dome shaped one, which is against the PVD process nature, must be obtained to eliminate its negative impact on the Vt variation. The MG trench entrance damage needs to be well controlled to form an acceptable incoming profile in the subsequent gap-fill. This flat bottom step coverage requirement in the TiAl film has raised new challenges for PVD sputtering. An experimental DOE was carried out to carefully tune the gas pressure, power, bias/source power ratio, etc, so that desired TiAl step coverage and subsequent void-free gap-fill were obtained, however, the gap-fill physical images are purposely not present here.Generically STI gap-fill is always challenging due to its high aspect ratio (AR). At 28nm, the gap-fill aspect ratios (AR) is 6 -7 when its patterning hard mask (HM) films are taken into account and the STI trench target CD is at ~ 60nm. Figure 1 below shows a typical incoming STI trench profile. For a complete gap-fill, it is necessary to have a HM recess by a wet chemical to widen the STI trench opening, followed by a deposition of ~ 200A oxide liner film. After the liner film, a commercially available SiCoNi dry etch

In this work, we report the application of flowable chemical vapor deposition (FCVD) technology in sub-20nm devices and flash devices. FCVD displays a strong ability in filling the gap of not only high aspect ratio straight vertical trench, but also re-entrant narrow profile as well as small horizontal trench. Through optimizing the annealing conditions, the as-obtained FCVD film can fully satisfy both the STI and ILD requirements which have different thermal budget. The FCVD oxide film also shows a better WET resistance than HARP film does.

No abstract

No abstract

The main purpose of this paper was to investigate formation of popcorn defect in low dielectric constant film (SiOCH, silicon oxycarbide) and put forward solution. To eliminate popcorn defect, the oxygen plasma post treatment was in situ used to remove suspended particle in chamber after the deposition of low dielectric constant film was finished. Scanning defect results showed that there were still buried defects with popcorn type in SiOCH low k film. When clean chamber process was adjusted, the quantities of the defects in SiOCH film were decreased. Moreover, deposited seasoning film covered all chamber after cleaning process, and its adhesion was directly relative with buried defect. For improving among chamber surface-seasoning film-SiOCH low k film, OMCTS/O2 in season process was adjusted from1.3/900 into 0.9/900, and the defect counts were decreased obviously. By optimizing cleaning and seasoning process, the buried defects were not found in SiOCH film.

No abstract