If the paper was written while you were in the employ of the company, the company may own the copyright of the paper. This will depend on the details of any agreement that you have with the company, and on how the paper relates to your employment.
If the paper was a purely spare-time activity, conducted outside of work hours and not related to your employment, you likely own the copyright, although you may have agreed to assign it to the company if you signed a rather far-reaching IP transfer agreement.
If the paper was written as part of your job, ("in the course of employment") the company quite likely owns the copyright, unless they granted such rights to you in an agreement.
If the paper was related to your job, but nor actually written as part of your job responsibilities, then the exact details of your employment agreement, and of the company's policies (which you may be considered to have agreed to) will determine the ownership.
The country where you were working and living when the paper was written will also matter.
If the company owns the copyright, then the company will decide if it will be licensed at all, and if so, under what license.
If you own the copyright, than any of several copy-left open-source licenses would achieve the results you desire. I would tend to favor the creative commons CC-BY-SA license (current version) as it is widely known and understood, but really almost any copy-left license will achieve the stated goals.
It might be a good idea to ask a company representative if they consider that they own the copyright to the specific paper. If the answer is "yes" and you disagree, you might well need a lawyer. Or you might be able to convince he company to release the paper under a license that will achieve your goal, depending on the nature of the paper and the company's policy on such matters, and the economic value of the paper to the company, if any. If the answer is "No" you have only to choose your specific license.