CN105870031B

CN105870031B - epitaxial growth monitoring pattern and monitoring method

Info

Publication number: CN105870031B
Application number: CN201610242891.0A
Authority: CN
Inventors: 王辉
Original assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Current assignee: Shanghai Huahong Grace Semiconductor Manufacturing Corp
Priority date: 2016-04-19
Filing date: 2016-04-19
Publication date: 2019-01-04
Anticipated expiration: 2036-04-19
Also published as: CN105870031A

Abstract

The invention discloses a kind of epitaxial growth monitoring pattern, the epitaxial growth monitoring pattern is divided into two groups of X and Y-direction, and every group all includes a closed hollow figure, and wherein there is vertical outline pattern in two outside of hollow figure horizontal direction of X block graphics；There is horizontal outline pattern in two outsides to the hollow figure of Y block graphics up and down, and the horizontal or vertical outline pattern has interval between hollow figure.This monitoring pattern can monitor caused image shift amount after epitaxial growth technology.The invention also discloses the monitoring methods of the epitaxial growth monitoring pattern.

Description

Epitaxial growth monitoring pattern and monitoring method

Technical field

The present invention relates to semiconductor integrated circuit manufacturing fields, particularly relate to a kind of epitaxial growth monitoring pattern, the present invention Also relate to the monitoring method of the epitaxial growth monitoring pattern.

Background technique

Superjunction (Surperjunction) structure would generally use extension in power MOSFET pipe Layer growth and boron ion injection are to realize.The epitaxial layer of introducing is thicker, more help to obtain low on-resistance and high-breakdown-voltage, And then improve the performance of super junction.Two-layer epitaxial structure (Double EPI) can obtain super thick epitaxial structure (20~30 μ m-thicks Degree) to significantly improve device performance, as shown in Figure 1.

But outer layer growth can cause pattern drifting in a certain direction, especially double epitaxial layer super-junction structures need through The thick epitaxial layer growth greater than 20 μm is crossed, the figure that growth will cause lower section can generate extremely serious distortion and offset, very To leading to component failure, if the left side is normal epitaxial patterns twice without offset in Fig. 2, and display is outer twice at the circle note of the right Prolong figure and has occurred that apparent offset.

Therefore the map migration amount for how monitoring epitaxial growth becomes one of the key of present superjunction devices exploitation.

Summary of the invention

Technical problem to be solved by the invention is to provide a kind of epitaxial growth monitoring pattern and monitoring methods, outer to monitor Prolong growing state.

To solve the above problems, the present invention provides a kind of epitaxial growth monitoring pattern, the epitaxial growth monitoring pattern point It is two groups of X and Y-direction, every group all includes a closed hollow figure, wherein the hollow figure level side of X block graphics There is vertical outline pattern to two outsides；There are horizontal outline pattern, institute in two outsides to the hollow figure of Y block graphics up and down There is interval between hollow figure in the horizontal or vertical outline pattern stated.

Further, the depth of the hollow figure is 2 ± 0.02 μm.

Further, the outline pattern is two parallel lines or groove, and length is 60~80 μm, and width is 2~2.5 μ M, height or depth are 2 μm.

The spacing of the outline pattern and intermediate hollow figure is 10~15 μm.

Further, the monitoring pattern is directly to make on a silicon substrate, or make in other film layers.

The monitoring method of epitaxial growth monitoring pattern of the present invention, includes following step:

Step 1 carries out lithographic definition on silicon substrate or other film layers and goes out monitoring pattern；

Step 2, etching form monitoring pattern；

Step 3 carries out epitaxial growth, also with the pattern of monitoring pattern after the epitaxial growth at monitoring pattern；

Step 4, epitaxial growth are completed, and the offset for measuring monitoring pattern in extension obtains the inclined of figure after epitaxy technique It moves.

Further, in the step three, the selective thick epitaxial layer directly grown that extension is 20~40 μm of thickness, It is divided into primary or multiple growth to be formed.

Epitaxial growth monitoring pattern and monitoring method of the present invention, are divided into X group and Y group for traditional monitoring pattern, X, Y both direction detect the case where epitaxial growth, deviated by the register of monitoring pattern before and after measurement epitaxial growth Amount is to realize the monitoring to epitaxy technique.

Detailed description of the invention

Fig. 1 is epitaxy technique schematic diagram.

Fig. 2 is that epitaxy technique generates map migration schematic diagram.

Fig. 3 is the schematic diagram of monitoring pattern X group of the present invention.

Fig. 4 is the schematic diagram of monitoring pattern Y group of the present invention.

Fig. 5~7 are monitoring method schematic diagrames of the present invention.

Fig. 8 is the offset that monitoring pattern of the present invention measures X-direction.

Fig. 9 is the offset that monitoring pattern of the present invention measures Y-direction.

Description of symbols

I is outline pattern length, and h is outline pattern width.

Specific embodiment

The present invention provides a kind of epitaxial growth monitoring pattern, and the epitaxial growth monitoring pattern is divided into the two of X and Y-direction Group, as shown in Figures 3 and 4 shown in, every group all includes a closed hollow figure, wherein in Fig. 3 X block graphics hollow There is vertical outline pattern in two outside of figure horizontal direction, i.e. the parallel vertical line of hollow figure two sides in Fig. 3.Y in Fig. 4 There is horizontal outline pattern in two outsides to the hollow figure of block graphics up and down, i.e. hollow figure upper and lower two is parallel in Fig. 4 Horizontal line.The horizontal or vertical outline pattern is spaced a distance f between hollow figure, distance f Generally 10~15 μm, and it is parallel to two opposite side of corresponding hollow.

The depth of the hollow figure is 2 ± 0.02 μm, that is, the tolerance for allowing to have ± 2%.

The outline pattern of X group or Y group is the two parallel lines or groove for protruding from epitaxial surface, length i is 60~ 80 μm, wide h is 2~2.5 μm, and height or depth are 2 μm.

Above-mentioned monitoring pattern can directly make on a silicon substrate, or make in other certain film layers.This prison Control figure not only can be used to monitor the offset of figure in thick epitaxial growth technology, can be used for other and involve the need for figure Shape deviates the technique or photoetching alignment mark for being monitored or measuring.

The monitoring method deviated using above-mentioned monitoring pattern to extension artwork shape, includes following step:

Step 1 carries out lithographic definition on silicon substrate or other film layers and goes out monitoring pattern, as shown in Figure 5.

Step 2, etching form the monitoring pattern, comprising X block graphics and Y block graphics, as shown in Figure 6.

Step 3, carries out epitaxial growth, and the selective thick epitaxial layer directly grown that epitaxial thickness k is 20~40 μm divides For primary or multiple growth formation.In epitaxial process, also there is monitoring pattern after the epitaxial growth at monitoring pattern Pattern.As shown in Figure 7.

Step 4, epitaxial growth are completed, and the offset for measuring monitoring pattern in extension obtains the inclined of figure after epitaxy technique It moves.It is measured to monitoring pattern X group and Y block graphics, compares the variation of the coordinate position of epitaxy technique front and back monitoring pattern, As shown in figure 8, Fig. 9 is the map migration of Y group monitoring, from figure it can be concluded that horizontal and vertical for the map migration of X group monitoring Map migration amount, offset variation amount is obvious before and after Y group extension, and display extension causes the map migration in Y-direction.

The above is only a preferred embodiment of the present invention, is not intended to limit the present invention.Come for those skilled in the art It says, the invention may be variously modified and varied.All within the spirits and principles of the present invention, made any modification, equivalent Replacement, improvement etc., should all be included in the protection scope of the present invention.

Claims

1. a kind of epitaxial growth monitoring pattern, it is characterised in that: the epitaxial growth monitoring pattern is divided into two groups of X and Y-direction, Every group all includes a closed hollow figure, and wherein two outside of hollow figure horizontal direction of X block graphics has vertical Outline pattern；There is horizontal outline pattern in two outsides to the hollow figure of Y block graphics up and down, and described is horizontal or vertical There is interval between hollow figure in outline pattern；The depth of the hollow figure is 2 ± 0.02 μm；Described is outer Block diagram shape is two parallel lines or groove, and length is 60~80 μm, and width is 2~2.5 μm, and height or depth are 2 μm；Described is outer Block diagram shape and the spacing of intermediate hollow figure are 10~15 μm.

2. epitaxial growth monitoring pattern as described in claim 1, it is characterised in that: the monitoring pattern is directly to serve as a contrast in silicon It makes on bottom, or is made in other film layers.

3. the monitoring method of epitaxial growth monitoring pattern according to claim 1, it is characterised in that: include following step It is rapid:

Step 2, etching form monitoring pattern；

Step 4, epitaxial growth are completed, and the offset for measuring monitoring pattern in extension obtains the offset of figure after epitaxy technique.

4. the monitoring method of epitaxial growth monitoring pattern as claimed in claim 3, it is characterised in that: in the step three, The selective thick epitaxial layer directly grown that extension is 20~40 μm of thickness is divided into primary or multiple growth and is formed.