CN101923281A

CN101923281A - Method for improving fidelity of Si/Ge emitter window graph

Info

Publication number: CN101923281A
Application number: CN2009100574274A
Authority: CN
Inventors: 王雷
Original assignee: Shanghai Hua Hong NEC Electronics Co Ltd
Current assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Priority date: 2009-06-17
Filing date: 2009-06-17
Publication date: 2010-12-22
Anticipated expiration: 2029-06-17
Also published as: CN101923281B

Abstract

The invention discloses a method for improving the fidelity of a Si/Ge emitter window graph, which comprises the following steps of: 1, designing a Si/Ge emitter window layout, namely (1) cutting a rectangular graph into three parts along a long axis direction in a central symmetry mode, allowing two end parts to have the same size, and allowing the rest part to be a middle part; (2) setting rational intervals between each of the two cut end parts and the middle part; (3) cutting the two end parts into a plurality of structures with holes at certain intervals; and (4) treating the middle part, namely splitting the middle part into a plurality of sets with graphs at certain intervals, or maintaining a whole rectangular structure without splitting; and 2, performing optical proximity correction by adopting the Si/Ge emitter window layout designed by the step 1, and forming a graph approximate to a square by utilizing a principle that a side lobe is generated when a hole of the layout is overexposed.

Description

Improve the method for Si/Ge emitter-window anti-aliasing degree

Technical field

The invention belongs to the manufacturing process field of Si/Ge device in the semiconductor manufacturing, the optics that is specifically related in the Si/Ge device photoetching process closes on modification method, relates in particular to a kind of method of the Si/Ge of raising emitter-window anti-aliasing degree.

Background technology

(Si/Ge refers to Si based on Si/Ge _xGe _1-xAlloy) semiconductor devices of compound, utilize the Si/Ge band gap than Si littler and with the characteristics of Si ic process compatibility, be fit to make high integration high-speed and easily and the Si semiconductor devices carry out the semiconductor devices of compatibility, be widely used in the high-speed communication field.

In the Si/Ge device, the general Si/Ge that uses is as the base, polysilicon is an emitter, doped substrate is as collector, the shape of emitter-window can influence the post-depositional thickness of emitter polycrystalline grid, Si/Ge CONCENTRATION DISTRIBUTION for doping of subsequent transmission utmost point polycrystalline grid and base exerts an influence, cutoff frequency and amplification coefficient to device have very big influence, so the anti-aliasing degree that how to be improved, it is most important parts in the whole Si/Ge photoetching process that the emitter-window that manufacturing process is obtained approaches design as far as possible.Existing optics closes on modification method often to be revised by increasing additional patterns, and its effect can not be satisfactory, and especially when size reduced, fidelity was poorer.

Summary of the invention

The optics that the technical problem to be solved in the present invention provides the anti-aliasing degree of emitter-window in a kind of Si/Ge of raising device closes on modification method.

For solving the problems of the technologies described above, the invention provides a kind of method of the Si/Ge of raising emitter-window anti-aliasing degree, comprise the steps:

Step 1, design Si/Ge emitter-window domain; Step 1 specifically comprises:

(1) rectangular graph is cut to three parts at long axis direction with figure along the center symmetry, the identical size of two end portions wherein, all the other are center section;

(2) two end portions and the center section that cuts out is provided with a rational spacing;

(3) with the two end portions cutting be the structure of several apertures at regular intervals;

(4) at last the centre is partly handled, can be split as the group of several figures at regular intervals, or keep a whole rectangular configuration not split;

Step 2 adopts the Si/Ge emitter-window domain of step 1 design to carry out optics and closes on correction, can produce the principle of secondary lobe when utilizing the aperture overexposure of described domain, makes it final formation and is similar to square figure.

Can increase following steps between step (3) and the step (4): add that at the aperture place at the edge of described two end portions the additional patterns that improves the anti-aliasing degree carries out the fidelity correction.

Described additional patterns is serif structure or hammehead structure.

The described center section of step (4) can keep a whole rectangular configuration not split, and perhaps is split as two rectangular configuration at regular intervals, or is split as the combination of a plurality of apertures at regular intervals.

Compare with prior art, the present invention has following beneficial effect: can improve the anti-aliasing degree of emitter-window in the Si/Ge device, thereby reduce because the cutoff frequency of the Si/Ge device that the emitter-window change of shape causes and the variation of amplification coefficient.

Description of drawings

Fig. 1 is the design cycle synoptic diagram of emitter-window domain of the present invention;

Fig. 2 is an emitter-window lithographic results simulation drawing, Fig. 2 (A) is traditional emitter-window lithographic results simulation drawing, Fig. 2 (B) is one of emitter-window lithographic results simulation drawing of the present invention (center section does not split), and Fig. 2 (C) is one of emitter-window lithographic results simulation drawing of the present invention (center section fractionation).

Embodiment

The present invention is further detailed explanation below in conjunction with drawings and Examples.

The optics that the invention provides a kind of Si/Ge of raising emitter-window anti-aliasing degree closes on modification method, mainly utilize a series of aperture figures to form Si/Ge emitter-window domain, utilize more little rectangle to produce the more little optical approach effect principle of radius-of-curvature of corner rounding (corner slynessization), simultaneously too small spacing can't imaging principle, bigger rectangle is split as aperture, corner rounding is less in the exposure back, figure more approaches domain, the intermediate section open region can be because lack of resolution after exposure simultaneously, and the edge can produce side lobe (secondary lobe during the aperture overexposure, secondary lobe) effect causes the principle of figure adhesion, makes it final formation and is similar to square figure.

The present invention will be split as three parts shown in Fig. 1 (D) as the represented traditional rectangle emitter-window figure of Fig. 1 (A) in accordance with the following methods:

(1) figure is cut to three parts at long axis direction with figure along the center symmetry, the identical size of two end portions wherein, all the other are center section, see Fig. 1 (B);

(2) two end portions and the center section that cuts out is provided with a rational spacing, sees Fig. 1 (C);

(3) being the structure of a series of several apertures at regular intervals with the two end portions cutting, seeing Fig. 1 (D), is example with 3 apertures;

(4) can add the additional patterns that improves the anti-aliasing degree at the aperture place at edge, as serif (serif) or tup (hammer head);

(5) at last the centre is partly handled, can be split as combination (two rectangles (seeing Fig. 2 (C)) for example, or be split as the combination of a plurality of apertures, or center section do not split, and forms a whole rectangular configuration (seeing Fig. 2 (B)) of a series of figures.

The present invention can also add comprehensive Mask bias according to demand.Mask bias refers on the true light shield difference of one times of figure and design.Lithographic process window is relevant with mask bias simultaneously, and different mask bias can make process window more optimize.Therefore can increase different mask bias according to the performance of photoetching process in actual the enforcement.General increase and decrease is of a size of 0%～50% of design size.Its embodiment is finished the back for all design configurations and is unified all figures are amplified and dwindle on domain.

Claims

1. a method that improves Si/Ge emitter-window anti-aliasing degree is characterized in that, comprises the steps:

Step 1, design Si/Ge emitter-window domain; Step 1 specifically comprises:

2. the method for raising Si/Ge emitter-window anti-aliasing degree according to claim 1, it is characterized in that, increase following steps between step (3) and the step (4): add that at the aperture place at the edge of described two end portions the additional patterns that improves the anti-aliasing degree carries out the fidelity correction.

3. the method for raising Si/Ge emitter-window anti-aliasing degree according to claim 2 is characterized in that described additional patterns is serif structure or hammehead structure.

4. the method for raising Si/Ge emitter-window anti-aliasing degree according to claim 1, it is characterized in that, the described center section of step (4) can keep a whole rectangular configuration not split, perhaps be split as two rectangular configuration at regular intervals, or be split as the combination of a plurality of apertures at regular intervals.