Surface acoustic wave convolver

Claim 2

In a monolithic surface acoustic wave convolver having an arrangement of piezoelectric film/insulator/semiconductive epitaxial film/high-concentrated semiconductive substrate, an improvement wherein said semiconductive epitaxial film has thickness L in the following range: W.sub.max <L≦W.sub.max +2 μm where Wmax is the maximum depletion width defined by: ##EQU7## where N is the impurity density of said epitaxial film, ni is the intrinsic carrier density of said epitaxial film, εs is the dielectric constant of said epitaxial film, k is the Boltsmann's constant, e is electron charges; and T is the absolute temperature.

Claim 3

A surface acoustic wave convolver of claim 1 wherein said semiconductor is silicon (Si), and impurity density N of said epitaxial film is in the following range: 1×10.sup.13 cm.sup.-3 ≦N≦1×10.sup.16 cm.sup.-3

Claim 4

A surface acoustic wave convolver of claim 1 wherein said semiconductor is GaAs.

Claim 5

A surface acoustic wave device of claim 1 wherein said insulator is SiO 2 .

Claim 6

A surface acoustic wave convolver of claim 1 wherein said piezoelectric film is made from ZnO.

Claim 7

A surface acoustic wave convolver of claim 1 wherein said piezoelectric film is made from AlN.

Claim 8

A surface acoustic wave convolver of claim 2 wherein the propagation mode of surface acoustic waves is Sezawa wave.

Claim 9

A surface acoustic wave convolver of claim 7 wherein the surface orientation of said Si is (110), and the propagation direction of a surface acoustic wave is [100].

Claim 10

A surface acoustic wave convolver of claim 7 wherein the surface orientation of said Si is (100), and the propagation direction of a surface acoustic wave is [110].

Claim 11

In a monolithic surface acoustic wave convolver having an arrangement of piezoelectric film/insulator/second semiconductive layer/first semiconductive layer/high-concentrated semiconductive substrate, an improvement wherein said second and first semiconductive layers are semiconductive epitaxial films which are opposite to each other in conduction type, and wherein thickness L of said semiconductive epitaxial film is in the following range: 1.sub.2 <L≦1.sub.2 +W.sub.m +2 μm where 1 2 is the thickness of said second semiconductive layer, and W m is expressed by: ##EQU8## where N 1 is the impurity density of said first semiconductive layer, ni is the intrinsic carrier density of said first semiconductive layer, εs is the dielectric constant of said first semiconductive layer, k is the Boltsmann's constant, e is the magnitude of electron charges, and T is the absolute temperature.

Claim 12

In a monolithic surface acoustic wave convolver having an arrangement of piezoelectric film/insulator/second semiconductive layer/first semiconductive layer/high-concentrated semiconductive substrate, an improvement wherein said second and first semiconductive layers are semiconductive epitaxial films which are opposite to each other in conduction type, and wherein thickness L of said semiconductive epitaxial film is in the following range: 1.sub.2 <L≦1.sub.2 +W.sub.m +2 μm where 1 2 is the thickness of said second semiconductive layer, and W m is expressed by: ##EQU8## where N 1 is the impurity density of said first semiconductive layer, ni is the intrinsic carrier density of said first semiconductive layer, εs is the dielectric constant of said first semiconductive layer, k is the Boltsmann's constant, e is the magnitude of electron charges, and T is the absolute temperature.

Claim 13

A surface acoustic wave convolver of claim 10 wherein said semiconductor is silicon (Si), and impurity density N 1 of said epitaxial film is in the following range: 1×10.sup.13 cm.sup.-3 ≦N.sub.1 ≦1×10.sup.16 cm.sup.-3

Claim 14

A surface acoustic wave convolver of claim 10 wherein said semiconductor is GaAs.

Claim 15

A surface acoustic wave convolver of claim 10 wherein said insulator is SiO 2 .

Claim 16

A surface acoustic wave convolver of claim 10 wherein said piezoelectric film is ZnO.

Claim 17

A surface acoustic wave convolver of claim 10 wherein said piezoelectric film is AlN.

Claim 18

A surface acoustic wave convolver of claim 11 wherein the propagation mode of surface acoustic waves is Sezawa wave.

Claim 19

A surface acoustic wave convolver of claim 16 wherein the surface orientation of said Si is (110), and the propagation direction of a surface acoustic wave is [100].

Claim 20

A surface acoustic wave convolver of claim 16 wherein the surface orientation of said Si is (100), and the propagation direction of a surface acoustic wave is [110].