Semiconductor device

• US 5,731,637 A
• Filed: 07/25/1996
• Issued: 03/24/1998
• Est. Priority Date: 07/28/1995
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yawata, Shigeo, Baba, Yoshiro, Osawa, Akihiko, Hori, Shizue
• Primary Examiner(s): Prenty, Mark V.
• Application Number:
  US08/687,032
• Time in Patent Office: 607 Days
• Field of Search: 257/607, 257/610, 257/611, 257/612, 257/617, 257/913, 438/473, 438/474, 438/475
• US Class Current: 257/611
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 21/2652 Through-implantation
• CPC Class Codes: H01L 21/3221 of silicon bodies, e.g. for gettering
• CPC Class Codes: H01L 29/083 Anode or cathode regions of thyristors or gated bipolar-mode devices
• CPC Class Codes: H01L 29/66363 Thyristors

Abstract

The object of the present invention is to provide a method of manufacturing high-performance, high-breakdown-voltage semiconductor devices which suppresses an increase in the junction leakage current due to heavy metal contamination without increasing the number of manufacturing steps. A method of manufacturing semiconductor devices according to the invention, comprises the steps of ion-implanting one or more elements selected from a group of silicon, carbon, nitrogen, oxygen, hydrogen, argon, helium, and xenon into at least one surface of a semiconductor substrate of a first conductivity type at a dose of 1×10¹⁵ cm^-2 or more to form a distortion layer, oxidizing the surface of the substrate to form an oxide film, ion-implanting impurities of a second conductivity type at a low concentration (a dose of less than 1×10¹⁵ cm^-2) via the oxide film into the one surface of the substrate, ion-implanting impurities of the second conductivity type at a high concentration (a dose of 1×10¹⁵ cm^-2 or more) via the oxide film into the other surface of the substrate, and forming a junction by heat treatment.

Claims

1. A semiconductor device comprising:

a semiconductor substrate of a first conductivity type;

surface regions of a second conductivity type that are formed by ion-implanting impurities of the second conductivity type into both of the top and bottom surfaces of the substrate and heat-treating the surfaces and that each have a junction formed between an inner portion of the substrate and said surface regions, two in total, wherein

one of said two surface regions of the second conductivity type is a first surface region with a high impurity concentration and the other is a second surface region with a low impurity concentration, an entire area of the second surface region including a distortion layer formed by ion-implanting at least one element selected from a group of silicon, carbon, nitrogen, xygen, hydrogen, argon, helium, and xenon; and

when the depth of a p-n junction section on the second surface region side from the surface of the second surface region is 10 μ

m or more, a carrier depletion layer in the p-n junction exists in a portion deeper than the depth of the distortion layer from the surface of the second surface region.

2. A semiconductor device comprising:

a semiconductor substrate of a first conductivity type;

surface regions of a second conductivity type that are formed by ion-implanting impurities of the second conductivity type into both of the top and bottom surfaces of the substrate and heat-treating the surfaces and that each have a junction formed between an inner portion of the substrate and said surface regions, two in total, wherein

one of said two surface regions of the second conductivity type is a first surface region with a high impurity concentration and the other is a second surface region with a low impurity concentration, the second surface region including a distortion layer formed by ion-implanting at least one element selected from a group of silicon, carbon, nitrogen, oxygen, hydrogen, argon, helium, and xenon, and

when the depth of a p-n junction section on the second surface region side from the surface of the second surface region is less than 10 μ

m, a high-concentration layer of the second conductivity type is formed locally near the p-n junction section on the second surface region side, and if the depth of the p-n junction section on the second surface region side from the second surface region is x_j and the depth of the end of a carrier depletion layer on the second surface region side from the surface of the second surface region side with a reverse bias being applied to the p-n junction section on the second surface region side is x_p, integration of the impurity concentration ranging from x_p to x_j in the second surface region with respect to depth gives a value larger than 2×

10 cm^-2.

3. A semiconductor device comprising:

a semiconductor substrate of a first conductivity type;

surface regions of a second conductivity type that are formed by ion-implanting impurities of the second conductivity type into both of the top and bottom surfaces of the substrate and heat-treating the surfaces and that each have a junction formed between the surface regions and an inner portion of the substrate, two in total, wherein

the entire areas of said two surface regions of the second conductivity type include distortion layers formed by ion-implanting at least one element selected from a group of silicon, carbon, nitrogen, oxygen, hydrogen, argon, helium, and xenon.

4. A semiconductor device comprising:

a semiconductor substrate of a first conductivity type and having two surfaces;

an epitaxial layer provided on at least one of the surfaces of said substrate;

a first surface region of the second conductivity type formed in one of the surfaces of said substrate by ion-implanting impurities of the second conductivity type into said epitaxial layer and said one of the surfaces of the substrate and heat-treating the epitaxial layer and said one of the surfaces of said substrate;

a second surface region of the second conductivity type formed in the other surface of said substrate by ion-implanting impurities of the second conductivity type into said other surface of said substrate and heat-treating said other surface of said substrate; and

two junctions, one formed between one of the surface regions and an inner portion of said substrate and the other formed between the other surface region and the inner portion of said substrate, wherein

an entire area of at least one of said first and second surface regions of the second conductivity type includes a distortion layer formed by ion-implanting at least one element selected from a group of silicon, carbon, nitrogen, oxygen, hydrogen, argon, helium and xenon.