A kind of method that detects the mask index
Technical field
The present invention relates to the mask transmission system, particularly relate to a kind of method that detects the mask index.
Background technology
In photoetching process, mask transmission system is the important composition subsystem of litho machine, mainly bears the work such as access, transmission, location and exchange of mask, can avoid the people directly to contact with mask and mask is caused damage.Existing mask up-down detent mechanism; Index (indexer) like the release of ASYST company of american semiconductor manufacturer; Comprise: laser sensing system, locking device, elevating mechanism; Wherein, elevating mechanism comprises direct current generator, belt and drive lead screw, and elevating mechanism drives the slide block that is connected to the mask chassis and does straight reciprocating motion along support post.Index provides superior performance with its servocontrol action accurately, intelligent locking setting and optimized carrier sensing (carrier sensing).
But; Mechanical loss takes place in the drive lead screw of the elevating mechanism of index, direct current generator and belt etc. easily; Make the performance of index reduce the normal transmission that influences mask; Common detection method all need be carried out when machine is out of service, because whole photoetching process is continuous can not interrupting, so conventional detection method is not suitable for this.Therefore, need a kind of method that can under the index duty, detect the index state.
Summary of the invention
The object of the present invention is to provide a kind of method that detects the mask index, under the index duty, to detect the index operation conditions.
A kind of method that detects the mask index comprises: measure the electric current of index circuit with multimeter, when the electric current of said index surpasses warning value, then will in following 2 months ~ 4 months, check index; When the electric current arrival dangerous values of said index, will check index in the week 1 week ~ 2, confirm whether each component wear situation of index is all normal.
A kind of method that detects the mask index of the present invention comprises: measure the electric current of index circuit with multimeter, when the electric current of said index surpasses warning value, then will in following 2 months ~ 4 months, check index; When the electric current arrival dangerous values of said index, will check index in the week 1 week ~ 2, confirm whether each component wear situation of index is all normal.
As preferably, obtain said warning value and dangerous values through test of many times.
As preferably, said warning value is 1.95A ~ 2.3A.
As preferably, said dangerous values is 2.3A ~ 2.5A.
The method of detection mask index of the present invention; Can under the index duty, detect the operation conditions of index; This method is nondestructive; Need not take machine apart each several part is detected, can in time safeguard and maintenance index through method of the present invention, to avoid unnecessary fault.
Description of drawings
Fig. 1 is the front elevation of mask index;
Fig. 2 is the side view of mask index;
Fig. 3 is the synoptic diagram of the elevating mechanism of mask index;
Fig. 4 is a kind of schematic diagram that detects the method for mask index of the present invention.
Embodiment
For make above-mentioned purpose of the present invention, feature and advantage can be more obviously understandable, does detailed explanation below in conjunction with the accompanying drawing specific embodiments of the invention.
Fig. 1 and Fig. 2 are respectively the front elevation and the side view of mask index, and wherein, 11 is the up-down chassis of index, can drive mask and move up and down; 12 is the base of index, plays a part to support and fix, and the control circuit board of index also is installed in it; 13 and/or 14 is the framework support post of index; Play a supportive role, the elevating mechanism on up-down chassis 11 also is installed in 14, as shown in Figure 3; Said elevating mechanism comprises direct current generator 31, belt 32 and drive lead screw 33; Belt 32 is given drive lead screw 33 with the transmission of power of direct current generator 31, and said drive lead screw 33 drives the slide block 34 that connects up-down chassis 11 and pumps along framework support post 13 and 14, up-down chassis 11 with and on mask move up and down along with slide block 34.
Respectively there is an index both sides of exposure bench.When the index failover shows the location mistake, and after the oneself detects, can not deal with problems the time, need change accessory with unloading on the index slave unit, this will take a long time.A kind of method that detects the mask index of the present invention is that a multimeter is connected index input and output both sides; Because index takes place when unusual; Can make the electric current that flows through it surpass normal level; Therefore, the present invention is through detecting the running status that its size of current detects the mask index.
Fig. 4 is a kind of schematic diagram that detects the method for mask index of the present invention, and 1 among the figure representes index, and said index 1 just is equivalent to the variable resistor among the figure, and multimeter 2 is connected on the input and output two ends of index 1.Adopt the ISIM simulation software, index is done the experiment of limit holding capacity, rule of thumb calculate a general warning value and dangerous values then.In the present embodiment; Be that (0kg (free time), 1.4Kg (sylphon), 1.6Kg (1 mask), 4.0Kg (6 masks), 5.0Kg (12 masks) and 8Kg (alarm current) carry out emulation for a plurality of loaded states of 7 pairs of mask indexs of APDSS to the model of the ASYST company of exposure bench both sides respectively; Draw the current output value under the index normal condition, as shown in table 1:
As shown in table 1, under normal circumstances, the electric current of index is no more than 1.93A, otherwise the electric current of index has very big jump, more than 2.3A; The scope of said warning value is 1.93A ~ 2.3A, and the scope of said dangerous values is 2.3 ~ 2.5A.In the present embodiment, the present invention is on above current value range, and according to the repeatedly experiment of index limit holding capacity, the electric current warning value that draws this index is 1.95A, and the electric current dangerous values is 2.3A.Current value that institute's multimeter is recorded and warning value and dangerous values are done comparison; If the electric current that multimeter is measured meets or exceeds warning value (1.95A), then will be in following 3 months index be checked and prepare associated components (such as direct current generator, screw mandrel and belt) simultaneously; If electric current meets or exceeds dangerous values (2.3A), will in a week, check index, confirm whether each component wear situation of index is all normal.
Obviously, those skilled in the art can carry out various changes and modification to the present invention and not break away from the spirit and scope of the present invention.Like this, belong within the scope of claim of the present invention and equivalent technologies thereof if of the present invention these are revised with modification, then the present invention also is intended to comprise these changes and modification interior.