New doping method for subhalf micron trench sidewalls by using an electron cyclotron resonance plasma

Surface and Coatings Technology

2004

121

Fundamentals of Pulsed Plasmas for Materials Processing André AndersLawrence Berkeley National Laboratory, University of California, 1 Cyclotron Road, Berkeley, California 94720-8223 AbstractPulsed plasmas offer the use of much higher power (during each pulse) compared to continuously operated plasmas, and additional new parameters appear such as pulse duty cycle. Pulsed processing may help meeting the demands of increasingly sophisticated materials processes, including thin film deposition, plasma etching, plasma cleaning of surfaces, and plasma immersion ion implantation. The high kinetic energy of ions allows processes to occur far from thermodynamic equilibrium. Pulsed plasmas are driven by external pulsed power sources, and one has to consider the power source and the plasma as a coupled system. The dynamic plasma impedance is a key quantity from an electrical engineering point of view.From a plasma physics point of view, one needs to consider the dynamics of plasma species, their density and energy distribution, ionization and recombination reactions, and, most importantly, the development of transient sheaths. Dimensionless scaling parameters are a useful tool putting the variety of plasma parameters in relation to characteristic quantities. This is illustrated by several examples of pulsed processes relevant to thin film deposition. The emerging technology of pulsed sputtering is discussed in detail including the possibility to achieve the mode of self-sustained self-sputtering during each pulse.3

Section: Transient Sheathsmentioning

confidence: 99%

“…Adler [16], Conrad [17], Mizuno [18], and others. By lowering pulsed bias from 10's of kV to much smaller values, and using condensable metal plasmas, plasma immersion technology was expanded into the field of interface engineering and film formation by energetic condensation [19].…”

Section: And Pulsed Substrate Biasmentioning

confidence: 99%

Fundamentals of pulsed plasmas for materials processing

Surface and Coatings Technology

2004

121

“…As conventional implanters are not adapted to very low ion energies, implantation of doping elements via PBII processing with a collisional sheath is becoming a useful tool for shallow implantation. Plasma doping (or PLAD) thus constitutes, by far, the most important application of PBII in microelectronics [10,21,23,[126][127][128][129][130][131][132][133][134], along with the production of SOI (silicon on insulator) wafers with the smart-cut process [135][136][137][138].…”

Section: Plasma Dopingmentioning

confidence: 99%

Plasma-based ion implantation and deposition: a review of physics, technology, and applications

Pelletier

IEEE Trans. Plasma Sci.

2005

169

After pioneering work in the 1980s, plasma-based ion implantation (PBII) and plasma-based ion implantation and deposition (PBIID) can now be considered mature technologies for surface modification and thin film deposition. This review starts by looking at the historical development and recalling the basic ideas of PBII. Advantages and disadvantages are compared to conventional ion beam implantation and physical vapor deposition for PBII and PBIID, respectively, followed by a summary of the physics of sheath dynamics, plasma and pulse specifications, plasma diagnostics, and process modelling. The review moves on to technology considerations for plasma sources and process reactors. PBII surface modification and PBIID coatings are applied in a wide range of situations. They include the by-now traditional tribological applications of reducing wear and corrosion through the formation of hard, tough, smooth, low-friction and chemically inert phases and coatings, e.g. for engine components. PBII has become viable for the formation of shallow junctions and other applications in microelectronics. More recently, the rapidly growing field of biomaterial synthesis makes used 1 of PBII&D to produce surgical implants, bio-and blood-compatible surfaces and coatings, etc.With limitations, also non-conducting materials such as plastic sheets can be treated. The major interest in PBII processing originates from its flexibility in ion energy (from a few eV up to about 100 keV), and the capability to efficiently treat, or deposit on, large areas, and (within limits) to process non-flat, three-dimensional workpieces, including forming and modifying metastable phases and nanostructures.We use the acronym PBII&D when referring to both implantation and deposition, while PBIID implies that deposition is part of the process.2

“…Already in the late 1980s, the concept of high-energy implantation of gaseous ions was extended to a process of lower bias voltage and energy that is suitable for doping of trenches of semiconductors [39,40]. Because the sheath dimension (millimeters or centimeters) is much larger than the dimension of the trenches (micrometer or less), ions can reach the sidewall of trenches only by collisions.…”

Section: Concept 5 Trench Doping Using Collisional Piii Sheathmentioning

confidence: 99%

From plasma immersion ion implantation to deposition: a historical perspective on principles and trends

Surface and Coatings Technology

2002

Plasma immersion techniques of surface modification are known under a myriad of names.The family of techniques reaches from pure plasma ion implantation, to ion implantation and deposition hybrid modes, to modes that are essentially plasma film deposition with substrate bias.In the most general sense, all plasma immersion techniques have in common that the surface of a substrate (target) is exposed to plasma and that relatively high substrate bias is applied. The bias is usually pulsed. In this review, the roots of immersion techniques are explored, some going back to the 1800s, followed by a discussion of the groundbreaking works of Adler and Conrad in the 1980s. In the 1990s, plasma immersion techniques matured in theoretical understanding, scaling, and the range of applications. First commercial facilities are now operational. Various immersion concepts are compiled and explained in this review. While gas (often nitrogen) ion implantation dominated the early years, film-forming immersion techniques and semiconductor processing gained importance. In the 1980s and 1990s we have seen exponential growth of the field but signs of slowdown are clear since1998. Nevertheless, plasma immersion techniques have found, and will continue to have, an important place among surface modification techniques.