The measuring method of the alignment precision between the different multiplying litho machine
Technical field
The present invention relates to the measuring method of the alignment precision between a kind of different multiplying litho machine.
Background technology
At present, a lot of semiconductor manufacturing industry companies all have the litho machine (company that for example has has 2X/4X/5X simultaneously) of different multiplying simultaneously, and the alignment precision between the litho machine of different multiplying all is to verify by the alignment precision between measurement and the standard film.Through after using repeatedly, the precision of standard film also can decrease.In this case, also need the standard light of polylith different multiplying to cut blocks for printing simultaneously, the polylith standard light not only cost height of cutting blocks for printing, and the polylith standard light cuts blocks for printing after using repeatedly, the also alignment deviation that may introduce.
Summary of the invention
Technical matters to be solved by this invention provides the measuring method of the alignment precision between a kind of different multiplying litho machine, it can not need standard film, record the alignment precision deviation between the different multiplying litho machine, the alignment deviation of avoiding the polylith standard light to cut blocks for printing and after using repeatedly, introduce.
In order to solve above technical matters, the invention provides the measuring method of the alignment precision between a kind of different multiplying litho machine, may further comprise the steps:
(1) parallel placement two row's resolution charts on the standard photo mask board: first row's resolution chart is the housing resolution chart with reference to photoetching multiplying power correspondence; Second row's resolution chart is the inside casing resolution chart of contrast photoetching multiplying power correspondence;
(2) use with reference to the litho machine of photoetching multiplying power and aim at first row's resolution chart, carry out photoetching process first time, formation housing litho pattern on silicon chip;
(3) aim at second row's resolution chart with the litho machine of contrast photoetching multiplying power, carry out the photoetching process second time, form the inside casing litho pattern in housing litho pattern scope;
(4) alignment of measurement housing litho pattern and inside casing litho pattern is poor, obtains with reference to the alignment precision difference between photoetching multiplying power litho machine and the contrast photoetching multiplying power litho machine.
On standard light is cut blocks for printing, make one group of resolution chart because the present invention adopts, can not need standard film, record the alignment precision deviation between the different multiplying litho machine, the alignment deviation of avoiding the polylith standard light to cut blocks for printing and after using repeatedly, introduce.
Description of drawings
Below in conjunction with the drawings and specific embodiments the present invention is described in further detail.
Fig. 1 is the synoptic diagram that standard light is carved the resolution chart on the mask plate in the one embodiment of the invention;
Fig. 2 is that the present invention adopts the figure after the photo mask board of Fig. 1 carries out photoetching.
Embodiment
As shown in Figure 1, the measuring method of the alignment precision between the different multiplying litho machine of the present invention parallel placement two row's resolution charts on the standard photo mask board at first: first row's resolution chart is the housing resolution chart with reference to photoetching multiplying power correspondence; Second row's resolution chart is the inside casing resolution chart of contrast photoetching multiplying power correspondence, above-mentioned two rows are set during resolution charts on photo mask board, the resolution chart zone is made up of transmission region and light tight zone, but not 1 of graphics field promptly can be a transmission region, also can be light tight zone.
Two row's resolution charts of the present invention can comprise plural resolution chart (as being respectively 3 among Fig. 1) respectively, first row is the housing resolution chart, all adopt 5X photoetching multiplying power for reference to the photoetching multiplying power resolution chart size to be set, the outer length of side of housing is 150nm among the figure, and the interior length of side is 100nm.This dimension of picture can be set as required, and it satisfies after the photoetching figure reduction magnification for reference to the photoetching multiplying power.Second row's resolution chart is the inside casing resolution chart, to be provided with according to contrast multiplying power to be measured, the length of side of three inside casing resolution charts is respectively 50nm (corresponding 5X photoetching multiplying power), 40nm (corresponding 4X photoetching multiplying power) and 20nm (corresponding 2X photoetching multiplying power) among the figure, above-mentioned size can be provided with as required, but need be proportional to the photoetching multiplying power of this inside casing resolution chart correspondence.
Set after the resolution chart of standard photo mask board, use with reference to the litho machine of photoetching multiplying power and aim at first row's resolution chart, carry out the photoetching process first time.For example to contrast the alignment precision difference of 5X photoetching multiplying power and 2X photoetching multiplying power, then aim at the housing resolution chart of the corresponding inside casing resolution chart of second row 2X photoetching multiplying power top, contrast the alignment precision difference of 5X photoetching multiplying power and 5X photoetching multiplying power, then aim at the housing resolution chart of the corresponding inside casing resolution chart of second row 5X photoetching multiplying power top.On silicon chip, form the housing litho pattern after the photoetching.
Aim at second row's resolution chart with the litho machine of contrast photoetching multiplying power then, be about to the position that photo mask board moves to the inside casing resolution chart of second row's contrast photoetching multiplying power correspondence downwards, carry out the photoetching process second time in housing litho pattern scope, form the inside casing litho pattern.
Adopt different contrast photoetching multiplying powers carry out after the photoetching photoetching alignment figure as shown in Figure 2, further measure the alignment poor (size A, B, C, D among the figure) of housing litho pattern and inside casing litho pattern, promptly obtain with reference to the alignment precision difference between photoetching multiplying power (5X) litho machine and contrast photoetching multiplying power (the being all 5X) litho machine, can obtain alignment precision difference between other different multiplying litho machines with quadrat method.
Measuring method of the present invention adopts makes one group of resolution chart on standard light is cut blocks for printing, can not need standard film, records the alignment precision deviation between the different multiplying litho machine, the alignment deviation of avoiding the polylith standard light to cut blocks for printing and introduce after using repeatedly.