Top surface imaging

Fig. 35. Process flow for thin-film imaging lithography (a) bilayer process and (b) top surface imaging. The bilayer process shown here employs a positive-tone imaging layer. The TSI process illustrated refles on preferential silicon incorporation in the exposed regions of the imaging layer to give a...

Fig. 5.9 FESEM images of TiOz nanotubes grown in formamide based electrolyte at 35 V for 48 hours showing (<0 cross-section at lower magnification, (b) cross-section at high magnification, and (c) top surface image.

Top-surface imaging through vapor phase siiyiation... 

Digital top-surface imaging using a vapor phase silylation... 

The three main approaches to multilayer resist imaging systems (see Chapter 16 for details) include (i) hard mask (HM) processes, (ii) top surface imaging (TSI) processes requiring latent image formation only near the surface of the resist, thus circumventing any transparency requirements, and (iii) bilayer resist (BLR)... 

Photoresists can be classified into three categories based on the lithographic processes single layer photoresists (SLRs), bilayer photoresists (BLRs), and top surface imaged (TSl) photoresists [5]. Single layer photoresists have traditionally been the work horse for patterning semiconductor devices due to its process simplicity as compared with the bilayer and the TSl processes. 

Figure 6. SEM top surface images, EDS data and nano indentation data from the coatings prepared by two elemental targets and single alloying target, respectively.

Top-Surface Imaging Using Selective Electroless Metallization of Patterned Monolayer Films... 

In contrast to the si tion processes in i ch the near-surface region is modified, far fewer aiq>roadies exist for direct man ulation of the top oaf ace of a substrate to provide high resolution patterns of etch resistant materials. The initial report of top-surface imaging (TSfi utilized selective deposition of TIOj on the photo-oxidized surface of hydrophobic pofymers (4, 5). 

In the deep UV region, exposure tools which use the conventional Hg lamps require fast resists (< 15 mj/cm ) in order to provide short exposure times and sufficient throughput. To meet the photospeed requirements, resists based on the incorporation of TBOC groufis onto the PHOST backbone pioneered the era of acid catalyzed amplified tems. Both negative, positive, and top surface imaging (TSI) resists based on TBOC have been formulated for the deep UV region (3, 5). 

For top surface imaging, after deep UV exposure, sflylation of the image was performed in the gas phase using N,N-diethylaminotrimethylsilane (DEATS) or in the liquid phase (HMCTS) using hexamethylcyclotrisilazane ill). Photospeed, resolution, and contrast were determined using 50 KeV IBM EL-3 electron beam, Brookhaven synchrotron X-ray radiation, GCA I line stepper, Perkin Elmer 500(deep UV mode) and ASM excimer laser deep UV stepper. 

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