IIIB-1 Electrical characteristics of small geometry MOSFETs with a bird's-beak free and fully recessed isolation structure

Borophosphosilicate glass (BPSG) with high dopant levels has been obtained by combining the low pressure TEOS‐borosilicate glass (BSG) and phosphosilicate glass (PSG) processes at an optimum deposition temperature of 620°C. The process has been improved with regard to uniformity and run‐to‐run stability by introducing the trimethlyborate used for the boron doping from the front end, while the phosphine employed requires a quartz injector. The BPSG layers exhibit good chemical stability and flow properties at 850°C as well as an excellent step coverage. The wet etch rate of BPSG and BSG is not changed by a N2 anneal. Experiments with BPSG and BSG showed that a void free trench filling is only feasible for trenches with tapered walls, but a heat‐treatment at 900°C reduces the cavities to small bubbles in the trench center and planarizes the surface. By using a rapid anneal system, an elimination of the bubbles as well as a totally planarized surface can be achieved with a 1100°C, 30s pulse for BSG with 6 weight percent boron.

Section: Recessed Isolationmentioning

confidence: 99%

Low Pressure Deposition of Doped SiO2 by Pyrolysis of Tetraethylorthosilicate (TEOS): I . Boron and Phosphorus Doped Films

Becker

Rohl

1987

“…An important application of silicon nitride films is their use as oxidation masks in the LOCOS process (1) and its numerous variants (SILO (2), FUROX (3), LOPOS (4), NOLOCOS (5), SWAMI (6)...).…”

mentioning

confidence: 99%

Thermal Oxidation in Wet Oxygen of Reactive Ion‐Beam Sputter‐Deposited Silicon Nitride Films

Fourrier

Bosseboeuf

Bouchier

et al. 1991

Oxidation kinetics of silicon nitride films in wet oxygen at 900 and 1000~ deposited at room temperature by ion-beam sputtering is studied. Two compositions of Si~.N, were used: quasistoichiometric (N/Si -1.4) and silicon-rich (N/Si = 0.8). The results are compared with similar experiments on low-pressure chemical vapor deposited silicon nitride and bare silicon substrates. The optical properties of silicon nitride bulk and the thickness of the layer formed during oxidation were measured by ellipsometry and characterized in depth by Auger profiles. Refractive index of ion-beam sputter-deposited films decreased during oxidation. This variation is explained by a reduction of disorder in the layer. The Auger analysis of oxidized silicon nitride films shows a three-layer system, SiOJSi~NuOJSi3N4, for the two compositions used. The intermediate oxynitride layer, of homogeneous composition in the case of sto]chiometric films, is thicker for the silicon-rich films and its composition is ~ariable with depth. However, the oxidation rate remains the same for the two compositions used. The experimental data are analyzed by using published oxidation models. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 141.211.4.224 Downloaded on 2015-06-29 to IP

“…One of the isolation techniques which is to a high degree compatible with these requirements is the Side WAll Mask Isolation or so-called SWAMI. This technique has first been proposed by Chiu et al (8) in 1982, and over the last six years several alternatives or modifications of the basic process flow have been evaluated and used quite successfully. The original SWAMI technique is rather vulnerable to dislocation generation near the vertical sidewalls during the field oxidation due to the presence of a rather thick nitride layer at the foot of the oxide sidewalls.…”

mentioning

confidence: 99%

Structural and Electrical Characterization of SWAMI Techniques for Submicron Technologies

Claeys

Vanhellemont

Cavioni

et al. 1989

The SWAMI (side wall masked isolation) technique has been implemented in several VLSI and ULSI process outlines, as it is characterized by a low bird's beak extension, interesting topographical features such as a smooth top surface after field oxidation, and a low substrate defect density. In this work both the structural properties and electrical characteristics of single and double silicon etched SWAMI techniques are investigated. A comparison is also made with standard LOCOS isolation techniques. It will be demonstrated that the double silicon etch SWAMI structure is a very appropriate isolation alternative for standard LOCOS. The good electrical performance coupled with the geometry advantages, i.e., a high planarization level and a low bird's beak extension, make SWAMI a suitable isolation technique for future ULSI processing schemes.