摘要:

SiN films for x‐ray mask membranes were prepared using a low pressure chemical vapor deposition system designed for high temperature deposition and low impurity incorporation. The physical and optical properties of the films such as stress, uniformity, optical transmittance, and absorption were investigated. Film composition and impurities were also evaluated. The SiN film deposited at a substrate temperature of 1000 °C showed suitable properties for x‐ray mask membrane, such as well controlled tensile stress of about 5×107Pa, high optical transmittance over 95% at 500 to 800 nm, and low impurity concentration.

ISSN:0734-211X    

DOI:10.1116/1.587394

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

In this article, the imaging principles of projection steppers for optical lithography, using standard transmission masks, are reviewed, and compared with the image formation using various types of phase shifting masks (PSM), in order to get a better insight in the working principles of the various PSM techniques. The printability of periodic lines using a standard transmission mask is compared with the use of an alternating shifter PSM and the dependence of imaging on spatial coherence is discussed extensively. Furthermore the imaging of isolated lines is discussed, using a bright field standard transmission mask, a chromeless phase edge PSM, and a dark field rim PSM. The coherence dependence of an alternated shifter is verified experimentally. Experiments also confirm the superior performance of a chromeless phase edge PSM to print isolated lines.

ISSN:0734-211X    

DOI:10.1116/1.587395

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

The problem of polymer contamination in W trench etching is studied for fluorocarbon plasmas. Polymer contamination of narrow trenches has been observed on samples where isolated positive‐relief structures (mesas) are clean. This effect is linked to sidewall sputtering by ions backscattered at low angles from the substrate: the sidewalls of a mesa are bombarded by reflected ions originating over a larger area of the substrate than the sidewalls of a trench. The presence of a blast of backscattered ions is confirmed (in an SF6/Br2plasma) by images where sidewalls adjacent to large substrate areas etch isotropically while those in the shadow of an adjacent feature etch anisotropically. Finally, it is shown that ultrathin, durable polymer coatings which protect mesa sidewalls without contaminating nanometer‐scale trenches can be formed in a magnetically enhanced, triode etching system using a CF4/O2source gas: 40 nm wide, 300 nm deep trenches are shown.

ISSN:0734-211X    

DOI:10.1116/1.587396

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

The effects of substrate temperature and position on the properties of Fe films deposited onto (100) GaAs substrates by ion beam sputtering were studied. Films were deposited on substrates at angular positions from −20° to 66°, with respect to the target surface normal, at temperatures from 100 to 500 °C. The deposition rate was higher in the forward scattered direction but decreased for angles greater than 45°. The macroscopic film stress was compressive at low temperatures but underwent a compressive to tensile transition between 300 and 500 °C. Furthermore, the stress varied with substrate position. The stress predicted from thermal expansion mismatch is tensile. Both the low temperature compressive stress and the variation of stress with position are qualitatively accounted for by an energetic bombardment or ‘‘atomic peening’’ process. For optimum deposition conditions, the films are highly (200) oriented, with rocking curves as narrow as 0.5°. The resistivity of the films approaches that of bulk Fe, and the variations of resistivity with deposition conditions appear to be associated with the crystallographic perfection of the films.

ISSN:0734-211X    

DOI:10.1116/1.587397

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

A process to coat submicron structures in paraffin resists, selectively with metals in a single vacuum cycle (all‐dry process), is demonstrated. The process includes the evaporation of paraffin on to a support, the generating of crosslinked areas by irradiation with electrons, the developing of the structure by heating the resist film, and finally a selective coating with metal. The degree of crosslinking of the paraffin film has a remarkably influence on the nucleation density of the metal and allows us to control on a very fine scale the area on which the metal is deposited.

ISSN:0734-211X    

DOI:10.1116/1.587398

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

ISSN:0734-211X    

DOI:10.1116/1.587399

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

ISSN:0734-211X    

DOI:10.1116/1.587400

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

We have reduced the gate voltage required to achieve a given emission current density in field‐emitter arrays by scaling down the gate‐to‐tip and tip‐to‐tip spacing to the unprecedented levels of 0.08 and 0.32 μm, respectively. The submicrometer features of our arrays are patterned using interferometric lithography. Electrical tests of arrays we have fabricated have shown a record low turn‐on voltage of 8 V for cesiated molybdenum emitters. Emission current densities of 1600 A/cm2have been obtained, which is also a record for such structures. These arrays provide large advantages for applications such as flat panel displays and microwave devices.

ISSN:0734-211X    

DOI:10.1116/1.587401

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

Silicon microtips for field emission applications were coated with thin silicon carbide layers by chemical vapor deposition (CVD) and plasma‐enhanced CVD (PECVD) at temperatures of 800 to 1200 °C using propane or a methane/propane mixture as carbon sources. Coatings from 4 to 30 nm thick were obtained. Scanning electron microscopy and Auger electron spectroscopy were used to investigate the morphology and composition of the carbonized tips. Both silicon carbide and pure carbon coatings could be formed depending on the process parameters used. Sharp carbonized tips were obtained by PECVD using propane flow concentrations.  

ISSN:0734-211X    

DOI:10.1116/1.587402

出版商:American Vacuum Society    

年代:1994

数据来源: AIP

摘要:

Cold‐cathode microdiodes with tungsten and heavily doped polycrystalline silicon emitters have been fabricated using silicon planar processing and solid‐state surface micromachining techniques. This work has focused on building reliability into vacuum microelectronic devices and eliminating the need for external vacuum pumping as commonly used in these devices. The following technology advances have been incorporated into sealed microdiode devices: (1) recessed cavities with lateral chemical etch delivery channels, (2) electron beam‐evaporated vacuum enclosures, (3) the use of atomic force microscopy to analyze the fine grain emitter surface structure, (4) the use of soft x‐ray photoelectron spectroscopy to determine surface chemical composition of cathode and anode surfaces, and (5) the use of ultraviolet photoelectron spectroscopy to measure as‐processed work function.

ISSN:0734-211X    

DOI:10.1116/1.587403

出版商:American Vacuum Society    

年代:1994

数据来源: AIP