摘要:

This report describes the synchrotron radiation (SR) flood exposure hardening process to improve the thermal stability in negative working x‐ray resist, based on Novolak resin, an acid generator and a crosslinker. This simple SR flood exposure hardening process renders sub‐half‐micron size images in novolak resist, which are resistant to flow at a higher temperature. Our investigation shows that resist images in SAL601‐ER7 resist remain thermally stable at 300 °C after SR flood exposure treatment. Study with infrared spectroscopy suggests that the activator (triazine) which produces strong acid to induced acid catalyzed condensation reaction in the resist film during lithographic exposure, is further decomposed as a result of the SR flood exposure treatment to catalyze further crosslinking of the melamine crosslinker with the novolak resin, during hardbaking to enhance the resist image thermal stability.

ISSN:0734-211X    

DOI:10.1116/1.585685

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

A single‐step image reversal lift‐off process is used to delineate micron wide patterns in silicon nitride films deposited at room temperature by reactive ion‐beam sputtering. Edges of lines perpendicular to the plane of incidence of the ion‐beam on the target during deposition were found to be asymmetrical. This result is explained by the tilting of angular distributions of sputtered nitrogen and silicon. It is further demonstrated that these films can be used as masks for the local oxidation of silicon without pattern degradation and with a weak penetration of oxide under the silicon nitride mask edge (known as the bird’s beak). Film‐induced stress has no influence on the bird’s beak configuration.

ISSN:0734-211X    

DOI:10.1116/1.585686

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

The tapered etching of aluminum CHF3/Cl2/BCl3gas mixtures in a hexode reactive ion etching reactor is reported. The process involves sidewall polymer deposition during etching; Auger analysis of the deposit showed mainly carbon and chlorine. The metal sidewall angle (taper angle) was studied as a function of processing conditions, the spacing between Al lines, and photoresist thickness. The extent of taper increased with increasing CHF3flow rates, saturating at high flow rates, and decreased with increasing Cl2flow rates. The extent of taper increased with bias in the range −190 to −230 V, and decreased in the range −230 to −260 V. In addition, the extent of taper increased with increasing spacing and with decreasing photoresist thickness. The taper angle for a given spacing can be tailored in the range 60°–90° by adjusting processing conditions. As expected, the step coverage of plasma‐enhanced TEOS oxide on taper‐etched aluminum lines showed a marked improvement over that of vertical aluminum lines.

ISSN:0734-211X    

DOI:10.1116/1.585687

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

Using aninsitudouble optical beam technique, the evolution of the strain for the Pt–Si system was followed before, during, and after reaction. During initial heating and prior to reaction only a compressive thermal stress is observed whereupon reaction to form Pt2Si yields a compressive intrinsic stress. The mechanism for stress buildup and relaxation is elucidated and shown to be related to the relative motion of Pt and Si atoms during the respective processes.

ISSN:0734-211X    

DOI:10.1116/1.585688

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

Progress in patterning technologies and computer‐aided circuit designs have brought us to the threshold of submicron dimensions in the fabrication of very large scale integrated circuits. For metallization at submicron dimensions, several requirements must be satisfied. In the present study we have prepared pure Al and Al–Y alloy films with different yttrium concentration by electron‐beam evaporation and evaluated several annealing characteristics for the Al–Y/(100)Si system by using a transmission electron microscope, scanning electron microscope, and measuring the electrical resistivity. We found that in the Al–0.7 wt % (0.2 at. %) Y alloy film annealed above 300 °C the electrical resistivity decreases to a value similar to that of a pure Al film, that is, 2.9 μΩ cm, and the same concentration of yttrium is also sufficient to minimize the generation and growth of annealing hillocks. These results are explained by the compositional and microstructural changes occurring in the Al–Y/(100)Si system.

ISSN:0734-211X    

DOI:10.1116/1.585689

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

A modulation‐doped Al0.3Ga0.7As/GaAs film with high mobility (11×104cm2/V s at 77 K) has been grown on a 4‐in. diam GaAs (100) substrate in a MBE system from Vacuum Generators. The variations of electrical parameters and thickness over the wafer are about ±2%, indicating good uniformities. The flux transient variations which influence the uniformity of stoichiometry in the growth direction are also investigated.

ISSN:0734-211X    

DOI:10.1116/1.585690

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

ISSN:0734-211X    

DOI:10.1116/1.585691

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

ISSN:0734-211X    

DOI:10.1116/1.585692

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

A bibliography has been compiled covering the production, control, and application of high brightness ion beams extracted from liquid metal and gas field ion sources. The development of this research field is studied, from its inception in the 1970’s in United States and United Kingdom research laboratories to its current status as a routine research tool used in the characterization and modification of a wide range of materials in laboratories worldwide. The increasing importance of Japanese research institutions in the development of new source materials and in the use of these beams in semiconductor materials modification is noted.

ISSN:0734-211X    

DOI:10.1116/1.585693

出版商:American Vacuum Society    

年代:1991

数据来源: AIP

摘要:

Focused ion beam (FIB) technique applications to very large scale integration (VLSI) failure analysis are reviewed. Three examples of microscopic cross sectioning andinsituobservation on a VLSI chip are presented. One is a cross section of an electromigration‐induced open circuit. Another shows a pinhole in the SiO2layer between the metal layer and the substrate. The third shows an open circuit, caused by process anomalies. Five preparation methods for further failure analysis are presented: cutting and connecting metal lines, making holes at insulation layer for electron beam probing, probing pad formation for mechanical and electron beam probing, microscopic cross sectioning for secondary electron miscroscopy observation, and marking for transmission electron spectroscopy observation. FIB was shown to be useful, as an aluminum microstructure observation tool, not only for qualitative observation of aluminum grains, but also for quantitative measurement of aluminum grain orientation. Each example is shown in many photographs.

ISSN:0734-211X    

DOI:10.1116/1.585694

出版商:American Vacuum Society    

年代:1991

数据来源: AIP