Manufacture of semiconductor device

[Detailed Description of the Invention]

[Industrial Application] * The present invention relates to the manufacturing method of the semiconductor device by which to form corrugation is needed for a photoresist film thick in a process. [Description of the Prior Art] In the semiconductor laser of the kind which changes, cycles are 3000 thru/or 4000 (to form the corrugation about a person] is needed.) to a substrate, for example. In order to form this corrugation, he forms on a substrate the mask which consists of 1 photoresist, and is trying to etch a substrate using that mask. By the way, in order to form the mask which consists of the above-mentioned photoresist, since the cycle of corrugation is detailed, applying the interference exposing method using a laser beam is performed. in order to expose a photoresist film with the application of the problem] above-mentioned interference exposing method which an invention tends to solve, since the light from a light source is weak, it is the thickness of a Off * Otho resist film 2000 (a person] grade -- even if thick, it must restrict to below a 3000 [person] grade.) Therefore, when unevenness exists in a substrate face in a photoresist film thin in this way, it is difficult to obtain what is used as a mask. The present invention is a very easy technique and makes it possible to form corrugation in a thick photoresist film. , [Means for Solving the Problem] In a manufacturing method of a semiconductor device of the present invention, on a substrate, a thick photoresist film is formed and it ranks next, When dry etching is carried out on it, an etching rate forms a small metal membrane more remarkable than photoresist, and ranks next, A photoresist film thin on it is formed, and it ranks next and ranks [ it depends on exposing and developing negatives with the application of the interference exposing method, and corrugation is formed in the thin photoresist film, and ] second to it, The dry etching method using suitable Enchantment to etch metal is applied, and by using the thin photoresist film as a mask, corrugation is formed in the metal membrane and it ranks second to it, Composition in which it comes to contain a process of applying the dry etching method using suitable etchant to etch photoresist, and forming corrugation in the thick photoresist film by using the metal membrane as a mask is taken. [Function] Because a thin photoresist film will be etched at first using the interference exposing method etc. if it depends on the above-mentioned composition, Even if the light of the light source which enforces the interference exposing method is weak, the pattern of corrugation can fully be formed, Etching the above-mentioned metal membrane into the pattern of corrugation by using as a mask the thin photoresist film processed such, it is very easy to etch the above-mentioned thick photoresist film into the pattern of corrugation by using the patterned metal membrane as a mask. [Example] Drawings 1 thru/or 5 are important section cutting side views of the semiconductor device in the process key point for explaining present invention 1 example, and they are explained hereafter, referring to figures, such as this. Refer to the 1st figure. + Depend on applying a+ spin coat method, and it is thickness~1 on In"P board 1. Photoresist film 2 about [mum] is formed. (b) Depend on applying the vapor-depositing method and it is thickness 150 on photoresist film 2. Cr film 3 about [people] is formed. Other metal, for example, Ti etc., can be substituted for Cr film 3. It depends on applying a fcl spin coat method, and is Cr film film very best thickness~800. Photoresist film 4 about [people] is formed. Refer to the 2nd figure. It depends on applying and developing the interference exposing method using a fdl laser beam, and is formation Touched about the pattern of corrugation to thin photoresist film 4. Refer to the 3rd figure. (e) Depend on applying the plasma etching technique using CF as etchant as a mask in thin photoresist film 4, etch Cr film 3, and form corrugation. Refer to the 4th figure. (It depends on applying the plasma etching technique using o2 as etchant as a mask in flcr film 3, thick photoresist film 2 is etched, and corrugation is formed.) Refer to the 5th figure. gl -- using thick photoresist film 2 as a mask -- as 1. Enchantment -- CC/-- depending on it being valid in the plasma etching technique using 2F2 -- corrugation IA deep enough to InP board 1 -- forming . Thus, manufactured InP board 1 can be used as a substrate in the semiconductor laser of a grating method. Although the above-mentioned example explained corrugation to jnP basis 'Fj and 1 about formation and the case where it carries out, If only it can form corrugation in thick photoresist film 2, it is not necessary to say that deep corrugation can be easily formed in S i O2 film or S i 3 N 4 film. [Effect of the Invention] A photoresist film thick on a substrate in the manufacturing method of the semiconductor device of the present invention, A metal membrane and a thin photoresist film are laminated in order, and the pattern of corrugation is formed in a thin photoresist film by the interference exposing method at first, It depends on This which uses the thin photoresist film as a mask, and carries out dry etching, and corrugation is formed in a metal membrane, and he depends on using the metal membrane as a mask and carrying out dry etching, and is trying to form corrugation in a thick photoresist film. Therefore, even if the light from the light source for enforcing the interference exposing method is weak, corrugation can be formed in a thick photoresist film as a result, and moreover, it is the corrugation, it is possible to consider it as a precise pattern like [ in order to form with the application of the dry etching method ] the case where the interference exposing method is applied to a thin photoresist film -- and Since the corrugation of a thick Off * Odo resist film can be formed, even if unevenness exists in the substrate face which should form corrugation using the thick photoresist film as a mask, the corrugation of precise and sufficient depth can be formed.

[Brief Description of the Drawings]

Drawings 1 thru/or 5 express the important section cutting side view of the semiconductor device in the process key point for describing present invention 1 example. In the figure, the corrugation by which 1 was formed in the InP board and IA was formed in InP board 1, a photoresist film with thick 2, and 3 show Cr film and the photoresist film with thin 4, respectively. Applicant for a patent The FUJITSU, LTD. representative patent attorney Phase Shoji Tani Representative patent attorney Watanabe Hiroshi - Drawing 1 Drawing 3