Low parasitic resistance contacts for scaled ULSI devices

Specific contact resistance measurements of metal-semiconductor junctions

“…The drive current of the transistor is determined by the total device resistance, which consists of the channel resistance and the parasitic resistances associated with diffusions and contacts. As device dimensions shrink in each new technology generation, contact resistance scales as a power of the reciprocal dimensions [4]. It is expected that the contact resistance between silicide and source/drain region will dominate the total series resistance.…”

Selective epitaxial growth of boron- and phosphorus-doped Si and SiGe for raised sources and drains

“…As far as MOSFETs are concerned, the fact that they are aggressively scaled down following the International Technology Roadmap for Semiconductors [2] puts stringent requirements on the source/drain junctions in terms of doping, shallowness and abruptness. One rather elegant method of meeting these prerequisites is to use Si or SiGe raised sources and drains (RSD) selectively grown in the active regions on each side of the gate stack [3][4][5][6][7][8][9][10][11]. This way, very shallow, quite heavily doped junctions can be formed, more material can be used up for silicidation (with, e.g.…”

Specific contact resistance and carrier tunneling properties of the silver metal/porous silicon/p-Si ohmic contact structure

“…The barrier height at the interface of the metal and the semiconductor is determined by the material, and surface state density or the surface doping concentration at the semiconductor surface [12]. In such case, the widely accepted tunneling model [27][28][29] assumes that the c is determined by the tunneling probability of the charge carriers through the Schottky barrier height (SBH) between the metal contact and the heavily doped semiconductor region. This model predicts that the dependence of the doping level (N s ) and barrier height (˚B) on the c is given by [29],…”

“…The value of the constant C 1 can be compared with the theoretical value of C 1 ∼ = 7.0 × 10 10 cm −3/2 eV −1 for the silicon [29] and previously reported value of C 1 = 1.45 × 10 10 cm −3/2 eV −1 for the Ag metal/PS/p-Si contact structure [18]. It can be inferred from the simulation that c ∼ = 2.62 × 10 −7 cm 2 can be obtained which represents the best c value achievable for the contact structure [29].…”