Quang khắc bằng chùm tia điện tử (Ebeam Lithography)

Quy trình quang khắc để tạo tranzitor. Gồm các nội dung: 1. Giới thiệu: Là phương pháp để tạo ra các chi tiết có độ chính xác cao, bằng cách chiếu một chùm tia điện tử lên lớp EResist nhạy với chùm tia đó. Đặc biệt là không cần dùng mask và thực hiện được với nhiều vật liệu. Tuy nhiên, phương pháp này khá phức tạp, chậm và tốn kém. 2. Ý tưởng của phương pháp 3. Phủ lớp Eresist 4. Tạo hình bằng chùm tia điện tử 5. Tráng rửa 6. Phún xạ 7. Hòa tan

E-Beam Lithography

G r o u p 7

P h u n g Va n T h o n g

N g u y e n V a n Tr o n g

Tr u o n g L e V a n

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Introduction

Basic Idea of E-Beam Lithography

E-Resist Spincoating

E-Beam Drawing

Developing

Sputtering

Lift-Off

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 Specialized technology for creating extremely fine patterns

 Basic: It uses a Beam of Electrons across a surface covered with a e-Resist film sensitive

Atributes:

 Used with very high resolution patterns

 No mask necessary like photolithography

 Can work with variety of materials

 But it’s complicated, slow and costs many millions of dollars 3

Basic Idea of E-Beam Lithography

5 basic steps:

E-Resist Spincoating

E-Beam Drawing

Developing

Sputtering

Lift-Off

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E-Resist Spincoating

Resist can be chemically changed under

exposure of the E-Beam

2 types: Possitive, Negative

One of first materials: Polymetyl Methacrilate(PMMA)

E-Resist was spun on the substrate and baked at 170-270

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C

°

E-Beam Drawing

 E-Beam is formed by a Electron

Gun after passing through Acceleration and a lot of and Lens

 Dose Equation: D= (I*t)/A

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JSM-840A Cross-section of column

Click to edit Master text styles

Second level

Third level

Fourth level

Fifth level

 Scattering when E-Beam penetrate the resist=> Electrons spread away and expose unexpected areas

 Forward Scattring (): When electrons enter Resist, they scatter in small

angle, cause broaden initial Beam Diameter

 Back Scattering (): As electrons pass through resist and enter substrate,

many will undergo large angle scattering events

These Electrons may return back in to the resist, causing additional exposure This is called Proximity Effect

Where

Effective diameter(nm) Resist thickness(nm) Acceleration voltage(KV)

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1.5

0.9( )t f

b

R d

V

=

f

d t

R

b

V

Dissolve all of exposed resist in a specific sovent, such as 1:3 mixture

of MIBK (methyl isobuthyl ketone) and Isopropanol (C3H8O)

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Sputter the desired thickness of metal on the wafer

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Soak the wafer in pirolidone or acetone to dissolve the remaining Resist

Final result:

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Etching Technology

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