H. K Sii

Hole trapping and trap generation in the gate silicon dioxide

Oxide breakdown has been proposed to be a limiting factor for future generation CMOS. The breakdown is caused by defect generation in the oxide. Although electron trap generation has received much attention, there is little information available on the hole trap generation. The relatively high potential barrier for holes at the oxide/Si interface makes it difficult to achieve a high level of hole injection. Most previous work was limited to an injec- tion level of 10 cm . In this paper, we investigate the hole trapping and trap generation when reaches the order of 10 cm . When cm , the trapping is dominated by the as-grown traps. As increases further, however, it is found that the generation of new traps controls the trapping. The trap gener- ation does not saturate up to the oxide breakdown. The trapping kinetics for both the as-grown and the generated traps is studied. The relationship between the density of generated traps and the is explored. Attention is paid to how the trapping and trap generation depends on the distance from the interface. In contrast to the uniform generation of electron traps across the oxide, we found that the hole trap generation was not uniform and it moved away from the interface as increased.

Mechanism for the generation of interface state precursors

The generation of interface states plays an important role in the degradation of submicrometer devices. Previous attention was mainly focused on the conversion between interface states and their precursors. The total number of defects, which is the sum of precursors and interface states, is often implicitly assumed to be constant. However, recent work indicates that this number could be increased. The mechanism for the generation of new precursors is still not clear and the objective of this article is to throw light on it. The work is concentrated on investigating the roles played by hydrogen and the holes trapped in the oxide. It is found that, although the H2 or the trapped hole alone does not create precursors, their simultaneous presence causes the damage. The hydrogen species can be either supplied externally or released within the device. The generation is thermally activated, but saturates at a defect-limited level. The generation kinetics is studied and the rate limiting mechanism is discussed. E...

Degradation of oxides and oxynitrides under hot hole stress

The impact of nitridation on hot hole injection and the induced degradation is quantitatively studied by comparing the behavior of a control oxide and oxynitrides. The oxynitride is prepared by either annealing the oxide in N/sub 2/O or growing directly in N/sub 2/O. The pMOSFETs are uniformly stressed by using the substrate hot hole injection technique. The physical quantities analyzed include the hole injection current, the density of created interface states and the density of trapped holes. It is found that a 30 min annealing in N/sub 2/O at 950/spl deg/C can enhance the effective barrier for hole injection by 0.6 eV. However, the interface state generation during the injection is insensitive to nitridation. The continuing degradation post the hole injection is also investigated. This includes a poststress interface state build-up and the generation of new precursors for interface states. The nitridation reduces the poststress degradation considerably. Where it is necessary, the hole induced degradation is compared with that induced by electrons. The applicability of the models proposed for oxynitrides to the present results is examined.

Relation between hole traps and hydrogenous species in silicon dioxides

Abstract There are at least two ways for creating positive charges in silicon oxides: hole trapping and the formation of positive hydrogenous species. This paper investigates the relation between them. The issues addressed include if hole traps assist in the generation of hydrogenous positive charges and how the formation of hydrogenous charges affects the hole trapping. Both reactive and non-reactive hydrogenous species are investigated and their different effects on hole traps are pointed out. It is found that there are two types of hole traps, having different relations with hydrogen.

Hole trap generation in gate dielectric during substrate hole injection

Defect generation in dielectrics under electrical stress is an important reliability issue for microelectronic devices. Most recent attention has focused on the generation of interface states and electron traps, while the creation of hole traps has rarely been reported. For example, there is hardly any information on the hole trap generation in oxynitrides and the generation under different temperatures has not been investigated. The objective of this work is to study the dependence of hole trap generation on temperature and nitridation. Based on new results, the role played by hydrogenous species in the generation is explored.

Relation between hydrogen and the generation of interface state precursors

Plasma charging and electrical stresses create new interface state precursors, which accelerate the device degradation during the subsequent stress. This paper investigates the mechanism responsible for the precursor generation. The attention is focused on the roles played by the hydrogen species and the holes trapped in the oxide. The properties of the generated precursor are studied and compared with those of precursors originally existed in the device.

Generation of hole traps in silicon dioxides

Oxide breakdown is a potential showstopper for future CMOS technology. Defect generation is responsible for the breakdown. Previous work (Degraeve et al., 2000; Stathis and DiMaria, 1999; Zhang et al, 1992) was focused on electron trap generation, while little information is available on hole trap generation. This paper unambiguously shows that a significant amount of hole traps can be created.