Patent EP0567075A2 successfully refreshed from Google Patents.
EP0567075A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A method for producing semiconductor device
Assignee: Denso Corp
•
Filing: 1993-04-20
•
Granted: —
•
Expires: 2013-04-20
Abstract
Abstract A method for producing a semiconductor device is capable of solving problems related to dicing a metal thin film used for electrochemical etching. According to the method, an n type epitaxial thin layer (36) is formed on a p type single-crystal silicon wafer (35). An n + type diffusion layer (38) is formed in a scribe line area on the epitaxial layer (36). An n + type diffusion layer (39) is formed in an area of the epitaxial layer (36) which corresponds to the predetermined part of the wafter (35). Aluminum film (40, 41) is formed over the diffusion layers (38, 39), respectively. The aluminum film (40) has a clearance (65) for passing a dicing blade (66). Predetermined parts of the wafer (35) are electrochemically etched by supplying electricity through the aluminum film (40), the diffusion layers (38) and (39), to leave predetermined parts of the epitaxial layer (36). The wafer (35) is diced into chips along the scribe line area. Each of the chips forms the semiconductor device. The electrochemical etching of the wafer (35) is carried out after the formation of the aluminum film (40, 41), by immersing the wafer (35) in a KOH aqueous solution (76) and by supplying electricity through the aluminum film (40). The electrochemical etching is terminated at an inflection point where an etching current inflects to a constant level from a peak level. During the electrochemical etching, the diffusion layer (39) reduces horizontal resistance in the epitaxial layer (36), so that the etched parts receive a sufficient potential to perform the etching.
Inventors
- 👤 Tsuyoshi Fukada
- 👤 Yoshimi Yoshino
- 👤 Yukihiko Tanizawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 21:41
CPC Classifications
B; B81; B81C; B81C1/00; B81C1/00865; B81C1/00888; B81C1/00015; B81C1/00134; B81C1/00158; G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0051; G01L9/0052; G01L9/0055; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/0802; G01P15/12; G01P15/123; H; H10; H10P; H10P50/00; H10P50/60; H10P50/61; H10P50/613; H10P54/00; B81B; B81B2201/00; B81B2201/02; B81B2201/0228; B81B2201/0235; B81C2201/00; B81C2201/01; B81C2201/0101; B81C2201/0111; B81C2201/0114; B81C2201/05; B81C2201/053; Y; Y10; Y10S; Y10S148/00; Y10S148/028; Y10S148/159; Y10S438/00; Y10S438/977
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
93 words
A method for producing a semiconductor device comprising: a first step of forming a single-crystal semiconductor thin film of second conduction type over a single-crystal semiconductor substrate of first conduction type; a second step of forming a conductive material in a scribe line area on the thin film; a third step of electrochemically etching the substrate with the conductive material transmitting etching electricity, to remove predetermined parts of the substrate; and a fourth step of dicing the substrate into chips along the scribe line area, each of the chips forming the semiconductor device.
Claim 2
Dependent Claim
15 words
The method according to claim 1, wherein the conductive material is a metal thin film.
Claim 3
Dependent Claim
24 words
The method according to claim 2, wherein the metal thin film has a clearance for passing a dicing blade along the scribe line area.
Claim 4
Dependent Claim
20 words
The method according to claim 1, wherein the conductive material is a high concentration diffusion layer of second conduction type.
Claim 5
Dependent Claim
19 words
The method according to claim 1, wherein the semiconductor thin film formed on the substrate is an epitaxial layer.
Claim 6
Dependent Claim
17 words
The method according to claim 1, wherein the third step leaves predetermined parts of the epitaxial layer.
Claim 7
Dependent Claim
26 words
The method according to claim 5, wherein a high concentration diffusion layer of second conduction type is formed in a predetermined area on the epitaxial layer.
Claim 8
Dependent Claim
41 words
The method according to claim 7, wherein the predetermined area on the epitaxial layer where the high concentration diffusion layer of second conduction type is formed corresponds to an area that is within a chip area and to be removed later.
Claim 9
Dependent Claim
45 words
The method according to claim 1, wherein the substrate is immersed in a KOH-based etching liquid and in electrochemically etched with a predetermined current, and the etching is stopped at an inflection point where the current inflects to a given level from a peak level.
Claim 10
Dependent Claim
18 words
The method according to claim 1, wherein the conductive material serves as an electrode during the electrochemical etching.
Claim 11
Dependent Claim
41 words
The method according to claim 4, wherein the second step firstly forms a high concentration diffusion layer of second conduction type in the scribe line area on the semiconductor thin film and then forms the conductive material on the diffusion layer.
Claim 12
Dependent Claim
46 words
The method according to claim 4, wherein, when the high concentration diffusion layer of second conduction type is formed as the conductive material, a high concentration diffusion layer of second conduction type is formed in a predetermined area within each chip area, of which removed liter.
Claim 13
Independent Claim
131 words
A method for producing a semiconductor device, comprising: a first step of forming an epitaxial layer of second conduction type over a single-crystal semiconductor substrate of first conduction type; a second step of forming a high concentration diffusion layer of second conduction type in a scribe line area on the epitaxial layer as well as a high concentration diffusion layer of second conduction type in a predetermined area within each chip area on the epitaxial layer; a third step of electrochemically etching predetermined parts of the substrate with the diffusion layer in the scribe line area serving as an electrode, to leave predetermined parts of the epitaxial layer; and a fourth step of dicing the substrate into chips along the scribe line area, each of the chips forming the semiconductor device.
Claim 14
Independent Claim
122 words
A method for producing a semiconductor device, comprising: a first step of forming a high concentration diffusion layer of second conduction type over a single-crystal semiconductor substrate of first conduction type and then an epitaxial layer of second conduction type over the diffusion layer; a second step of forming a high concentration diffusion layer of second conduction type in a scribe line area on the epitaxial layer; a third step of electrochemically etching predetermined parts of the substrate with the diffusion layer in the scribe line area serving as an electrode, to leave predetermined parts of the epitaxial layer; and a fourth step of dicing the substrate into chips along the scribe line area, each of the chips forming the semiconductor device.
Claim 15
Dependent Claim
45 words
The method according to claim 13, wherein the second step also forms a leak preventive high concentration diffusion layer of first conduction type on the periphery of a chip forming area of the epitaxial layer, the depth of the leak preventive layer reaching the substrate.
Claim 16
Dependent Claim
45 words
The method according to claim 14, wherein the second step also forms a leak preventive high concentration diffusion layer of first conduction type on the periphery of a chip forming area of the epitaxial layer, the depth of the leak preventive layer reaching the substrate.
Claim 17
Independent Claim
141 words
A method for forming a semiconductor device having a high concentration diffusion layer of first conduction type within each chip area, comprising: a first step of forming an epitaxial layer of second conduction type over a single-crystal semiconductor substrate of first conduction type; a second step of forming the high concentration diffusion layer of first conduction type within each chip area on the epitaxial layer as well as a high concentration diffusion layer of first conduction type in a scribe line area on the epitaxial layer; a third step of electrochemically etching predetermined parts of the substrate with the diffusion layer in the scribe line area serving as an electrode, to leave predetermined parts of the epitaxial layer; and a fourth step of dicing the substrate into chips along the scribe line area, each of the chips forming the semiconductor device.
Claim 18
Dependent Claim
45 words
The method according to claim 17, wherein the second step also forms a leak preventive high concentration diffusion layer of first conduction type on the periphery of a chip forming area of the epitaxial layer, the depth of the leak preventive layer reaching the substrate.
Claim 19
Independent Claim
168 words
A method for producing a semiconductor device having a high concentration diffusion layer within each chip area and metal film for the high concentration diffusion layer, comprising: a first step of forming an epitaxial layer of second conduction type over a single-crystal semiconductor substrate of first conduction type; a second step of forming the high concentration diffusion layer in a predetermined area within each chip area on the epitaxial layer; a third step of forming the metal film for the high concentration diffusion layer within each chip area and forming a Schottky junction by directly connecting an etching metal electrode to a scribe line area on the epitaxial layer; a fourth step of electrochemically etching predetermined parts of the substrate by applying a forward voltage of the Schottky junction caused by electricity through the etching metal electrode, to leave predetermined parts of the epitaxial layer; and a fifth step of dicing the substrate into chips along the scribe line area, each of the chips forming the semiconductor device.
Claim 20
Independent Claim
146 words
A method for producing a semiconductor device having a diaphragm (a thin part) and an integrated circuit section with electrode on the same substrate, comprising: a first step of forming a semiconductor layer of second conduction type over a single-crystal semiconductor substrate of first conduction type; a second step of forming the integrated circuit section with electrode on the semiconductor layer; a third step of forming electrode in a scribe line area on the semiconductor layer and electrically connecting the electrode in the scribe line area to the electrode of the integrated circuit section; a fourth step of electrochemically etching predetermined parts of the substrate with the electrode in the scribe line area transmitting electricity, to form the diaphragm from the semiconductor layer; and a fifth step of dicing the substrate into chips along the scribe line area, each of the chips forming the semiconductor device.
Claim 21
Dependent Claim
38 words
The method according to claim 20, wherein the third step electrically connects the electrode in the scribe line area to the electrode of the integrated circuit section through a high concentration diffusion layer formed on the semiconductor layer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.