摘要:

Projection imaging with the deep‐UV (193 nm) and vacuum ultraviolet (VUV) (157 nm) output of an excimer laser has been applied to submicrometer patterning of thin films by injected‐defect, surface‐chemical, and solid‐transformation processing. The methods have been designed to take advantage of the short‐wavelength, high‐peak‐intensity pulsed radiation from these sources. Examples are described of pattern definition by exposure of multilayer organic resists, by maskless etching and doping of solids in reactive vapors, and by solid‐state chemical transformations in inorganic Al/O films. Well‐resolved 0.4‐μm lines and spaces have been achieved. Required doses, between 0.04 and 1 J/cm2, are compatible with single‐ or multipulse step‐and‐repeat projection patterning with a small excimer laser.

ISSN:0734-211X    

DOI:10.1116/1.583226

出版商:American Vacuum Society    

年代:1985

数据来源: AIP

摘要:

A modulated‐beam, mass spectrometer system has been used to obtain information about etch products, reaction probabilities, and etching mechanisms for the reactions of Cl2with Al(100) and Cu(100) and for the reaction of XeF2with W(111) and Nb. The influence of ion bombardment on the etching reaction has also been investigated.

ISSN:0734-211X    

DOI:10.1116/1.583301

出版商:American Vacuum Society    

年代:1985

数据来源: AIP

摘要:

Profile control in plasma etching of polysilicon is described. Reactive gases are CCl2F2–H2and CCl2F2–C2H6. Undercutting suppression and sloped wall pattern profile without undercutting are realized. Thin film formation on the etched pattern side wall is observed. These characteristics are explained by the plasma polymerization phenomena which occurs competitively with etching reaction.

ISSN:0734-211X    

DOI:10.1116/1.583203

出版商:American Vacuum Society    

年代:1985

数据来源: AIP

摘要:

Fabrication of small‐area Nb/Nb‐oxide/Pb alloy Josephson junctions with areas defined by newly developed double insulating layers is described, and their measured current–voltage characteristics are presented in order to study the deviation in dc Josephson current in these junctions. The deviation in 1.69 μm2junctions is found to be within ±9% of the current’s mean value. This deviation is mainly due to the deviation in junction size.

ISSN:0734-211X    

DOI:10.1116/1.583229

出版商:American Vacuum Society    

年代:1985

数据来源: AIP

摘要:

A single‐step lift‐off process using chlorobenzene soak on AZ4110 resist is described. The effects of the soak time and temperature on the thickness of the overhang is presented. This process provides thick overhang with vertical side walls, which are essential for the successful lift‐off. Finally, the effect of deep UV exposure on the lift‐off is discussed.

ISSN:0734-211X    

DOI:10.1116/1.583240

出版商:American Vacuum Society    

年代:1985

数据来源: AIP

摘要:

A two‐lens optical system for a focused ion beam system has been designed, using a four‐electrode accelerating lens as the condenser lens and an Einzel lens as the objective lens. A 1 nA beam current in a 0.055–0.1 μm beam spot is obtained under the following conditions: 20 μA/sr angular current intensity, 10 eV beam energy spread, 30–60 kV acceleration voltage, and 4 mrad object side beam half angle. The chromatic aberration coefficient of the condenser lens is reduced by picking out the dominant design parameters and optimizing them under the design constraints. The four‐electrode accelerating lens has an object‐side chromatic aberration coefficientCco=11 mm at the object side focal lengthfo=25 mm at infinite magnification for 30 kV acceleration voltage. The Einzel lens operating in the acceleration mode has an image‐side chromatic aberration coefficientCci=70 mm at the image‐side focal lengthfi=50 mm. A focused ion beam system is developed using the designed lenses and a Ga ion source. A pattern as fine as 0.15 μm with excellent definition is obtained.

ISSN:0734-211X    

DOI:10.1116/1.583278

出版商:American Vacuum Society    

年代:1985

数据来源: AIP

摘要:

Factors affecting the ultimate resolution of ion beam lithography are discussed. These factors are primary ion scattering, recoil atom scattering, range of secondary electrons, and resist properties (i.e., resist sensitivity and molecule size in the resist). From a consideration of these factors, it is estimated that minimum linewidths of ≲10 nm can be achieved in polymethyl methacrylate (PMMA) using light ions. For heavy ions such as gallium, the resolution limit is estimated to be ∼30 nm with the limitation being due to recoil atom scattering. Fabrication of high resolution silicon nitride stencil masks is described and replication of the masks with protons in PMMA is demonstrated with features as small as 20 nm.

ISSN:0734-211X    

DOI:10.1116/1.583288

出版商:American Vacuum Society    

年代:1985

数据来源: AIP

摘要:

A focused ion beam (FIB) technology has many advantages for submicron structure fabrication and other maskless processes. In order to develop 4–16 M(D) RAM, the FIB technology is strongly desired for its capability of submicron lithography without proximity effects.

ISSN:0734-211X    

DOI:10.1116/1.583289

出版商:American Vacuum Society    

年代:1985

数据来源: AIP

摘要:

Submicrometer resolution ion beam resist exposure using a new type of stencil mask is described. The mask uses a grid support structure in transmission areas to remove restrictions on pattern geometry and improve stability. The image of the grid is eliminated by rocking the incident angle of the ion beam during exposure, or by special processing of the resist. We describe the mask fabrication sequence and show examples of masks that employ a 320 nm period grid structure. Patterns with a minimum feature size of less than one‐half micrometer have been replicated using this type of mask with both single and multilayer resists. In addition, experiments are described which used low energy ion beams to test the ultimate resolution of stencil masks without grid support. 40 nm wide lines were printed in PMMA at a mask‐to‐wafer gap of 25 μm. The applicability of such masks in high resolution proximity printing systems is discussed.

ISSN:0734-211X    

DOI:10.1116/1.583291

出版商:American Vacuum Society    

年代:1985

数据来源: AIP

摘要:

The use of a focused ion beam (FIB) system with a 0.2 μm beam diameter to fabricate npn bipolar transistors by maskless implantation of B (75 keV, 30 mA/cm2) is described. Devices with a conventional boron implant are fabricated on the same wafer. The material (SIMS profile,Rs) and electrical properties (transistorI–Vcharacteristics) of the FIB implants are comparable to those for conventional implants. Initial evaluation suggests that the lateral spread of the implanted area is<0.1 μm. The similarity in results between the two implant processes demonstrates that the FIB system is functioning as designed (no serious problems with beam pointing stability, target current fluctuations, or introduction of impurities, etc.) and that no significant differences in beam target interactions (dopant distribution, percent activation, residual defects, etc.) occur. Application of an FIB lateral base implant to prevent emitter current crowding is discussed and the fabrication of transistors with lateral profiles demonstrated.

ISSN:0734-211X    

DOI:10.1116/1.583292

出版商:American Vacuum Society    

年代:1985

数据来源: AIP