Under Policy R30.03, SFU's Intellectual Property Policy, instructors own copyright in their research and their teaching materials, including lectures (both written notes and the "performance" of the lecture), slide presentations and exams. This means that generally, students cannot film your lecture, copy your notes or slides, or post these materials online without your permission.
However, students still have the users' rights outlined in the Copyright Act, which means that within the limits of fair dealing, they can copy short excerpts of your work without permission.
Additionally, you are required to accommodate students who need teaching materials in alternate formats due to a disability. Students registered with the Centre for Accessible Learning (CAL) can record your entire lecture or copy your slides if they need to. These copies are for their own personal use only, though, and cannot be shared or posted online. Such students should identify themselves to you in advance. Contact the Centre for Accessible Learning (formerly: the Centre for Students with Disabilities) with any questions about these requirements.
You are welcome to inform your students that they cannot record your lectures; the Copyright Office provides sample syllabus text you can use, or you can write your own.
Contact the Copyright Office (email@example.com) with any questions.