JPS62219553A - Resistor - Google Patents

Abstract

PURPOSE:To maintain the excellent linearity of resistance up to higher electric field without raising the carrier temperature by a method wherein semiconductor layers with the same conductivity type but different carrier concentration are alternately laminated in the current flowing direction. CONSTITUTION:A resistor is composed by alternately laminating semiconductor layers 3, 4 with the same conductivity type but different carrier concentration in the current flowing direction. Joule's heat is generated as usual in the low carrier concentration layer 4 comprising N-type Si 0.1mum thick in the current flowing direction in impurity concentration of 1X10<17>cm<-3> but less heat is generated due to weak electric field in the high carrier concentration layer 3 comprising N-type Si also 0.1mum thick in the current direction in impurity concentration of 1X10<18>cm<-3> to be let off in lattice efficiently due to the high carrier concentration. Through these procedures, the heat generated in the low carrier concentration is let off in the lattice not only on the spot but also through the high concentration carrier layer 3 not to raise the electron temperature. In other words, the linearity of resistance can be maintained up to the electric field higher than usual field.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to the structure of a resistor made of a semiconductor.

(Prior art and its problems) When a high electric field is applied to a resistor made of a semiconductor, the carrier mobility decreases due to so-called hot electrons, and the resistance becomes nonlinear, causing problems in terms of application. This phenomenon occurs because the temperature of the carrier increases, and it occurs even if the resistor, that is, the crystal lattice, is cooled.

FIG. 2(a) is a schematic cross-sectional view showing a typical resistor. When a current is passed from electrode 1 to electrode 2, Joule heat is generated in the low carrier concentration layer 4. FIG. This heat mainly escapes to the crystal lattice, but does not escape to the two electrodes because they are far apart. Therefore, as shown in FIG. 2(b), the internal electron temperature rises, carrier mobility decreases, and I
It exhibits nonlinear resistance in electric fields above.

The object of the present invention is to eliminate the above drawbacks and provide a resistor structure in which the resistance is less likely to become non-linear due to hot electrons.

(Means for Solving the Problems) The present invention is composed of a resistor in which semiconductor layers of the same conductivity type and different carrier concentrations are alternately stacked in the direction of current flow.

(Example) FIG. 1(a) is a cross section showing an example of the resistor of the present invention!
It is. Thickness in current direction: 0.1 pm Impurity concentration: 1×1
Low carrier concentration layer 4 made of n-type 8i of 017 cm-3
In this case, Joule heat is generated as in the conventional example.

However, if the thickness in the current direction is 0.1 pm, the impurity concentration lXl0
In the high carrier concentration layer 3 made of n-type Si of 18 cm -3 , the electric field is weak, so there is little heat generation, and the high carrier concentration allows heat to be efficiently released to the lattice. Therefore, the heat generated in the low carrier concentration layer 4 not only escapes to the lattice on the spot, but also escapes to the lattice through the high concentration carrier layer 3, so that the electron temperature does not rise much as shown in FIG. 1(b). In other words, the linearity of resistance is maintained up to higher electric fields than in the conventional example. In this example, linearity was maintained up to 2×10 4 v/cm.

Such a structure can be made by laminating the high carrier concentration layer 3 and the low carrier concentration layer 4 with a thickness of about 100 layers in a controlled manner using MBE technology.

Further, in the above embodiments, the case where the carrier is an electron has been described, but the present invention also includes a case where the carrier is a hole. Further, in the above embodiment, the plurality of high and low carrier concentration layers 3 and 4 arranged alternately have the same concentration, but the present invention is not limited to this, and for example, adjacent high carrier concentration layers may have different concentrations.

(Effects of the Invention) 3°, 2) As is clear from the above explanation, according to the present invention, a resistance with good linearity can be realized up to a higher electric field without lowering the carrier temperature.

[Brief explanation of drawings]

FIG. 1(a) is a schematic cross-sectional view of a semiconductor resistor according to the present invention, 1 and 2 are electrodes, 3 is a high carrier concentration layer, 4 is a low carrier concentration layer, and FIG. 1(b) is a schematic cross-sectional view of a semiconductor resistor according to the present invention. FIG. 3 is a distribution diagram of electron temperature in the resistor of a). FIG. 2(a) is a schematic cross-sectional view of a semiconductor resistor having a conventional structure. FIG. 2(b) is a distribution diagram of the electron temperature in FIG. 2(a).

Claims (1)

[Claims] A resistor characterized in that semiconductor layers of the same conductivity type but with different carrier concentrations are stacked alternately in the direction of current flow.