CN103246167A

CN103246167A - Lithographic micromachining method

Info

Publication number: CN103246167A
Application number: CN2012100236621A
Authority: CN
Inventors: 汤浩泉
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-02-03
Filing date: 2012-02-03
Publication date: 2013-08-14

Abstract

A lithographic micromachining method is characterized in that extremely-small light spots are made through a self-focusing lens and a self-focusing fiber, and lithographic machining of chips to be machined of large-scale and very-large-scale integrated circuits is carried out through the combination of a certain quantity of the self-focusing fibers. A lithographic technology of computer CPU and camera CCD chips is introduced in the concrete implementation way of the invention.

Description

A kind of smooth micro-processing method

Technical field

The present invention is the technical bottleneck of current microelectronics manufacture field, is mainly used in the photoetching process of extensive and VLSI (very large scale integrated circuit).

Background technology

The photoetching process level of the current U.S. is the highest, and INTEL, AMD chip photoetching process are representative, and also there is quite level in Japan in this field, if can make high precision CCD chip.

Description

America and Japan lead and bounds ahead of China at microelectronic, on photoetching technique China are adopted strict blockade on new techniques, and the present invention has thoroughly broken the technical monopoly of America and Japan in the microelectronics photoetching technique.The making that the present invention focuses on small spot on the photoetching technique hereinafter forms, and briefly introduces the photoetching process of computer CPU chip and video camera CCD chip then in embodiment.

The making of nm level small spot forms very important on the photoetching technique, make nm level small spot, must make special optical fiber (hereinafter being referred to as self-focusing optical fiber), what self-focusing optical fiber was made will make special preform earlier, the index distribution of this preform such as accompanying drawing 1, the refractive index of preform core central point is starkly lower than core edge, change (generally being to rise) from prefabricated rods core central point to the core edge refractive index curve, the refractive index curve that must guarantee to make excellent core central area correspondence is significantly depression, a MCVD who uses in the world at present at the overall refractive index curve, PCVD, the manufacture craft of preforms such as VAD all can be produced this preform.The optical fiber that is drawn out by this preform is exactly self-focusing optical fiber, index distribution such as the accompanying drawing 2 of self-focusing optical fiber from the core to the edge.And the GRIN Lens of fiber optic applications field widespread use at present, also be to be drawn by this preform to form, only obviously greater than the core diameters of self-focusing optical fiber, its index distribution from the core to the edge is also as accompanying drawing 2 for the core diameters of GRIN Lens.Self-focusing optical fiber has tangible gathering effect to the light beam of transmission therein, light beam is to transmitting more complicated therein, here be not described in detail, here only provide GRIN Lens to the effect synoptic diagram of light beam, as accompanying drawing 3, to inciding the low-angle incident beam of GRIN Lens core, what light was walked is that curve and light are drawn close to the center, exit end forms small light spot, thereby plays the self-focusing effect.To import self-focusing optical fiber through GRIN Lens from the light beam of LASER Light Source outgoing, can not directly produce very small hot spot, also to adopt some measures, as accompanying drawing 4, to do some turn (not influencing under the transmission situation of light) along different solid angle direction in more local places than long self-focusing optical fiber more, the light that transmits in optical fiber like this is paraxial ray, light beam is ceaselessly pressed thin pressure narrow in transmission course, after than longer transmission distance, just can obtain very small hot spot at the exit end of self-focusing optical fiber.What deserves to be mentioned is that in self-focusing optical fiber is regulated optical fiber in the local area bending direction and flexibility, can finely tune the very small hot spot of outgoing with respect to the exit end fibre core position of optical fiber, it is very important that this implements photoetching simultaneously to many optical fiber.Because the application of this very small hot spot has great dirigibility, will be the application that example is introduced this very small hot spot with computer CPU chip and video camera CCD chip in the embodiment later.

Description of drawings

Accompanying drawing 1 is expressed the preform rod core refractive index profile of making self-focusing optical fiber, and d shows excellent diameter, d among the figure ₁Show excellent core diameter, n ₀Show excellent core central point refractive index, n ₁Show excellent core largest refractive index place refractive index, n ₂Table rod cladding refractive index.

Accompanying drawing 2 is expressed self-focusing optical fiber refractive index profile, d ₂The table core diameter, n ₃Table core centre point refractive index, n ₄Table fibre core largest refractive index place refractive index, n ₅Table rod cladding refractive index, c shows covering.

Accompanying drawing 3 is expressed GRIN Lens light transmission synoptic diagram.

Accompanying drawing 4 is expressed the installment state of self-focusing optical fiber on transmission path.

Accompanying drawing 5 is expressed the naked self-focusing optical fiber arranged distribution synoptic diagram for processing computer CPU chip, the naked self-focusing optical fiber of 1 table among the figure.

Accompanying drawing 6 is expressed the CCD chip base plate plane synoptic diagram of producing through lithography process, 2 table doped semiconductor unit among the figure, and 3 table metals are rectangular, and 4 show not doped semiconductor area.

Accompanying drawing 7 is expressed light sensitive layer distribution schematic diagram on the CCD chip base plate, 5 table CCD chip base plates among the figure, 6 table silicon dioxide layers, the blue light sensitive layer of 7 tables, 8 green light sensitive layers, the red light sensitive layer of 9 tables.

Accompanying drawing 8 is expressed CCD chip upper cover plate floor map, and 10 table metals are rectangular among the figure, 11 table doped semiconductor unit, and 12 show not doped semiconductor area.

Accompanying drawing 9 is expressed the naked self-focusing optical fiber arranged distribution synoptic diagram for processing video camera cpu chip, the naked self-focusing optical fiber of 13 table tables among the figure.

Embodiment

The small spot photoetching process is mainly used on extensive and the VLSI (very large scale integrated circuit), for breaking the technical monopoly of u.s.a. and japan on computer CPU and video camera CCD chip, briefly introduces out the photoetching process of the two hereinafter respectively.

For the photoetching process on the computer CPU chip, several hundred million transistor components and parts are generally arranged on the computer nowadays cpu chip, because a self-focusing optical fiber can only provide a small spot, only with a self-focusing optical fiber computer CPU is treated that the photoetching chip carries out photoetching, natural time is long and unrealistic, want to make several hundred million transistor components and parts by lithography at several square centimeters of chips, nature need form combination by a large amount of living many self-focusing optical fibers, need the tail optical fiber separately of multifiber is shelled into naked fibre, very strictness neatly and cleanly merges becomes an optical fiber outgoing group and makes each optical fiber exit end strictness in the same plane, as accompanying drawing 5, an optical fiber outgoing group generally has up to ten thousand optical fiber, each optical fiber all has clarification in certain roles, each root optical fiber only is responsible for the naked fine diameter class of transverse and longitudinal optical fiber zone, be furnished with computer-controlled electrooptical switching and be furnished with independent computer-controlled program (whether electrooptical switching control has light incident) at the incident end of each optical fiber, a special slip-stick artist only need be responsible for the circuit of some optical fiber photoetching, cooperatively interacted by a group slip-stick artist and to finish the photoetching process of entire chip, whole optical fiber group is that integral body is done small precession, and its small precession will be merged the small precession arrestment mechanism enforcement of current mechanical clock technology and micrometer caliper technology.

For the photoetching process on the video camera CCD chip, the characteristics of CCD chip are each photosensitive unit basically identicals, this neat requirement to the optical fiber group is higher, the making of CCD chip generally has following several flow process: (1) makes the CCD chip and turns in one's mind low, on making equally distributed parallel metal bar (interval between the bonding jumper is the length of side of square sensitivity speck) integral body, CCD chip base plate optical graving applies layer of silicon dioxide earlier, apply layer of semiconductor more thereon, make each square sensitivity speck below become the doping point through photoetching process, this is a utmost point of the sensitization electric capacity of square sensitivity speck correspondence, planimetric map such as accompanying drawing 6.

(2) apply layer of silicon dioxide at the CCD chip end of turning in one's mind, be coated with blueing, green, red trichromatism coating more thereon successively, as accompanying drawing 7.

(3) make CCD chip loam cake, it also is to make at base plate earlier to spread extremely narrow bonding jumper, apply silicon dioxide layer again, apply semiconductor layer (this layer semiconductor printing opacity) more thereon, same semiconductor doping point by each sensitivity speck correspondence of photoetching process, this is another utmost point of the corresponding sensitization electric capacity of square sensitivity speck, as accompanying drawing 8.(loam cake will be given adjacent two rectangular energisings of metal and only need the rectangular energising of metal at the end of turning in one's mind when noting the some sensitivity speck of scanning.)

(4) with loam cake by on the high-power microscope cover alignment and be stained with close fixing.

In sum, can not as making the computer CPU chip, adopt fairly large optical fiber group, because it is simple to make CCD chip photoetching circuit, in making CCD chip photoetching process, can be for a long time with the continuous working of self-focusing optical fiber exit end rectilinear translation, so the translation of optical fiber need can not arrange the many naked tail optical fiber exit ends of self-focusing optical fiber such as accompanying drawing 9 strict neat dislocation, and utilize high-power microscope comprehensively to locate like this with complicated computer program control.The big moving direction of whole self-focusing optical fiber outgoing group is direction shown in the arrow in the accompanying drawing 9, and vertical direction only can be done small precession with it, and this like this optical fiber group just can be made high precision CCD chip.

As for the used CCD chip of military satellite, adopt monochromatic sensitization, the photoetching process that it just need be more stricter than common CCD chip because all be.

Claims

1. GRIN Lens is characterized in that: drawn by preform and form, the core refractive index of the centre is lower than the core edge refractive index, changes as accompanying drawing 2 from the core center to the core edge refractive index curve.

2. self-focusing optical fiber, it is characterized in that: the fiber core refractive index of the centre is lower than the core edge refractive index, changes as accompanying drawing 2 from the core center to the core edge refractive index curve.

3. the method for making of a small spot is characterized in that: incident light is imported self-focusing optical fiber through GRIN Lens, the self-focusing optical fiber local area is done turning with compression light beam more so that obtained small spot at the self-focusing optical fiber exit end along different directions.

4. photoetching method, it is characterized in that: with the many naked fine proper alignment of self-focusing optical fiber exit end, the incident end of each root optical fiber is controlled entering so that each root optical fiber carries out photoetching separately of incident light by the electrooptical switching of independent computer program control, and whole group optical fiber carries out the entire circuit chip and carries out photoetching.

5. a photoetching method is characterized in that: the many naked fine exit ends of self-focusing optical fiber optical fiber afterbody are neatly misplaced arrange as accompanying drawing 9, carry out photoetching by rectilinear translation shown in the accompanying drawing 9.