## IMPURITY DIFFUSION COEFFICIENTS

TEMPERATURE ("C)

TEMPERATURE (°С) |

TEMPERATURE (°С) |

(b)

FIGURE D10.1

Impurity diffusion coefficients in (a) Si (I = (After Refs 1-3)

I, S = substitutional), (b) Ge, and (c) GaAs

**[1]**s2

[2] 4

ELECTRIC FIELD ST (kV/cm)

[3] Anodically grown oxide, in plasma or in solution.

inversely proportional to frequency, a capacitor can block DC signals while being able to couple AC signals. It can be used to bypass components at high

[5] L m

when carriers are in the mobility regime, velocity saturation regime, or ballistic regime, respectively. These equations assume that there is negligible barrier limiting the injection of carriers. In the case of an SIT, the barrier created by the gate bias controls the onset of the SCL current. In other words, SCL current starts when the 0* is lowered by VD to approximately zero. Because of this, VD in Eqs. (24.13) to (24.15) has a threshold value and should be replaced by (VD + aVG) where a is another constant similar in nature to 77 and 0.26 With this substitution, the SCL current becomes a function of Vq. Also, comparing Eq. (24.13) to Eq. (24.12), one can now see more clearly the fundamental difference between an analog transistor and an SIT. As discussed by Nishizawa, in an analog transistor, the SCL current does not have an exponential

[6] J I Nishizawa, E Iwanami, S Aral, M Shimbo, K Tanaka and A Watanabe, “Low-power SITL IC,” IEEE J Solid-State Circuits, SC-17, 919 (1982)

[7] J I Nishizawa, T Tamamushi, Y Mochida and T Nonaka, “High speed and high density static induction transistor memory,” IEEE J Solid-State Circuits, SC-13, 622 (1978)

[8] A Yusa, J 1 Nishizawa, M Imai, H Yamada, J I Nakamura, T Mizoguchi, Y Ohta and M Takayama, “SIT image sensor Design considerations and characteristics,” IEEE Trans Electron Dev, ED-33, 735(1986)

[9] Fiber-optics communication: An LED can be the light source in optical-fiber communication. The structure for a surface-emitting LED is shown in Fig. 47.7. Edge-emitting LED can also be used in this application. For

## Добавить комментарий